Rocksolid Light

Welcome to novaBBS (click a section below)

mail  files  register  newsreader  groups  login

Message-ID:  

Chemist who falls in acid is absorbed in work.


tech / sci.bio.paleontology / Polar dinosaurs

SubjectAuthor
* Polar dinosaursJohn Harshman
+* Re: Polar dinosaursOxyaena
|`* Re: Polar dinosaursJohn Harshman
| `* Re: Polar dinosaursOxyaena
|  `- Re: Polar dinosaursJohn Harshman
+- Re: Polar dinosaursJTEM
`* Re: Polar dinosaursTrolidous
 `* Re: Polar dinosaursOxyaena
  `* Re: Polar dinosaursTrolidous
   `* Re: Polar dinosaursOxyaena
    `* Re: Polar dinosaursTrolidous
     `* Re: Polar dinosaursPeter Nyikos
      `* Re: Polar dinosaursTrolidous
       `- Re: Polar dinosaursPeter Nyikos

1
Polar dinosaurs

<O42dnU2Z6Zi7Rkj9nZ2dnUU7-dHNnZ2d@giganews.com>

 copy mid

https://www.novabbs.com/tech/article-flat.php?id=3133&group=sci.bio.paleontology#3133

 copy link   Newsgroups: sci.bio.paleontology
Path: i2pn2.org!i2pn.org!weretis.net!feeder8.news.weretis.net!news.uzoreto.com!tr1.eu1.usenetexpress.com!feeder.usenetexpress.com!tr1.iad1.usenetexpress.com!border1.nntp.dca1.giganews.com!nntp.giganews.com!buffer1.nntp.dca1.giganews.com!news.giganews.com.POSTED!not-for-mail
NNTP-Posting-Date: Fri, 25 Jun 2021 08:33:25 -0500
Newsgroups: sci.bio.paleontology
X-Mozilla-News-Host: news://text.giganews.com:119
From: jharsh...@pacbell.net (John Harshman)
Subject: Polar dinosaurs
Date: Fri, 25 Jun 2021 06:33:24 -0700
User-Agent: Mozilla/5.0 (Macintosh; Intel Mac OS X 10.15; rv:78.0) Gecko/20100101 Thunderbird/78.11.0
MIME-Version: 1.0
Content-Type: text/plain; charset=utf-8; format=flowed
Content-Language: en-US
Content-Transfer-Encoding: 8bit
Message-ID: <O42dnU2Z6Zi7Rkj9nZ2dnUU7-dHNnZ2d@giganews.com>
Lines: 36
X-Usenet-Provider: http://www.giganews.com
X-Trace: sv3-4PC6/QZix3FnjNkmr7/r7YMYAzDb2mgt1XD8DJJDkALcT24oCFMeCQtl4A/P+4TKhpYhDABrSfG0GBs!ecNRRQXW/v9i4i+KWZgukowP9XazLoFAXfAHubokDwb1tKlz4NQkbxu81ZL3SUQPDcqgg1GdefY=
X-Complaints-To: abuse@giganews.com
X-DMCA-Notifications: http://www.giganews.com/info/dmca.html
X-Abuse-and-DMCA-Info: Please be sure to forward a copy of ALL headers
X-Abuse-and-DMCA-Info: Otherwise we will be unable to process your complaint properly
X-Postfilter: 1.3.40
X-Original-Bytes: 3283
 by: John Harshman - Fri, 25 Jun 2021 13:33 UTC

Here's the currently hot (pun unintended) news on dinosaurs at the poles:

https://www.cell.com/current-biology/fulltext/S0960-9822(21)00739-9

Fossils of the young of many species, good evidence that they nested
there, which is interpreted as evidence that they lived there
year-round, interpreted as further evidence of endothermy. There are
tyrannosaurids, hadrosaurs, ceratopsians, dromaeosaurs, and perhaps
pachycephalosaurs.

Here's the abstract (called "summary", but potato potahto):

"The unexpected discovery of non-avian dinosaurs from Arctic and
Antarctic settings has generated considerable debate about whether they
had the capacity to reproduce at high latitudes—especially the
larger-bodied, hypothetically migratory taxa. Evidence for dinosaurian
polar reproduction remains very rare, particularly for species that
lived at the highest paleolatitudes (>75°). Here we report the discovery
of perinatal and very young dinosaurs from the highest known
paleolatitude for the clade—the Cretaceous Prince Creek Formation (PCF)
of northern Alaska. These data demonstrate Arctic reproduction in a
diverse assemblage of large- and small-bodied ornithischian and theropod
species. In terms of overall diversity, 70% of the known dinosaurian
families, as well as avialans (birds), in the PCF are represented by
perinatal individuals, the highest percentage for any North American
Cretaceous formation. These findings, coupled with prolonged incubation
periods, small neonate sizes, and short reproductive windows suggest
most, if not all, PCF dinosaurs were nonmigratory year-round Arctic
residents. Notably, we reconstruct an annual chronology of reproductive
events for the ornithischian dinosaurs using refined
paleoenvironmental/plant phenology data and new insights into dinosaur
incubation periods. Seasonal resource limitations due to extended
periods of winter darkness and freezing temperatures placed severe
constraints on dinosaurian reproduction, development, and maintenance,
suggesting these taxa showed polar-specific life history strategies,
including endothermy."

Re: Polar dinosaurs

<sb5672$j7q$1@solani.org>

 copy mid

https://www.novabbs.com/tech/article-flat.php?id=3134&group=sci.bio.paleontology#3134

 copy link   Newsgroups: sci.bio.paleontology
Path: i2pn2.org!i2pn.org!weretis.net!feeder8.news.weretis.net!feeder5.news.weretis.net!news.solani.org!.POSTED!not-for-mail
From: oxya...@invalid.invalid (Oxyaena)
Newsgroups: sci.bio.paleontology
Subject: Re: Polar dinosaurs
Date: Fri, 25 Jun 2021 14:10:43 -0400
Message-ID: <sb5672$j7q$1@solani.org>
References: <O42dnU2Z6Zi7Rkj9nZ2dnUU7-dHNnZ2d@giganews.com>
Mime-Version: 1.0
Content-Type: text/plain; charset=utf-8; format=flowed
Content-Transfer-Encoding: 8bit
Injection-Date: Fri, 25 Jun 2021 18:10:43 -0000 (UTC)
Injection-Info: solani.org;
logging-data="19706"; mail-complaints-to="abuse@news.solani.org"
User-Agent: Mozilla/5.0 (Windows NT 10.0; Win64; x64; rv:78.0) Gecko/20100101
Thunderbird/78.11.0
Cancel-Lock: sha1:gD0cgmD2kHgPEsWy2PUw7xIghKQ=
Content-Language: en-US
In-Reply-To: <O42dnU2Z6Zi7Rkj9nZ2dnUU7-dHNnZ2d@giganews.com>
X-User-ID: eJwNy8kBwCAIBMCWJMKi5bAc/Zdg5j+2IUhXGNTG5qAVKWSoq8n9hEvqZoVyUsAdAvdyVq8T3aD94y7M9mY8WtQWGw==
 by: Oxyaena - Fri, 25 Jun 2021 18:10 UTC

On 6/25/2021 9:33 AM, John Harshman wrote:
> Here's the currently hot (pun unintended) news on dinosaurs at the poles:
>
> https://www.cell.com/current-biology/fulltext/S0960-9822(21)00739-9
>
> Fossils of the young of many species, good evidence that they nested
> there, which is interpreted as evidence that they lived there
> year-round, interpreted as further evidence of endothermy. There are
> tyrannosaurids, hadrosaurs, ceratopsians, dromaeosaurs, and perhaps
> pachycephalosaurs.
>
> Here's the abstract (called "summary", but potato potahto):
>
> "The unexpected discovery of non-avian dinosaurs from Arctic and
> Antarctic settings has generated considerable debate about whether they
> had the capacity to reproduce at high latitudes—especially the
> larger-bodied, hypothetically migratory taxa. Evidence for dinosaurian
> polar reproduction remains very rare, particularly for species that
> lived at the highest paleolatitudes (>75°). Here we report the discovery
> of perinatal and very young dinosaurs from the highest known
> paleolatitude for the clade—the Cretaceous Prince Creek Formation (PCF)
> of northern Alaska. These data demonstrate Arctic reproduction in a
> diverse assemblage of large- and small-bodied ornithischian and theropod
> species. In terms of overall diversity, 70% of the known dinosaurian
> families, as well as avialans (birds), in the PCF are represented by
> perinatal individuals, the highest percentage for any North American
> Cretaceous formation. These findings, coupled with prolonged incubation
> periods, small neonate sizes, and short reproductive windows suggest
> most, if not all, PCF dinosaurs were nonmigratory year-round Arctic
> residents. Notably, we reconstruct an annual chronology of reproductive
> events for the ornithischian dinosaurs using refined
> paleoenvironmental/plant phenology data and new insights into dinosaur
> incubation periods. Seasonal resource limitations due to extended
> periods of winter darkness and freezing temperatures placed severe
> constraints on dinosaurian reproduction, development, and maintenance,
> suggesting these taxa showed polar-specific life history strategies,
> including endothermy."

*Cryolophosaurus* is one of those aforementioned polar dinosaurs. I'm
surprised they consider the discovery of dinosaurs in the Arctic and
Antarctic to be "surprising." The poles weren't always frosty
wastelands, it'd make sense for dinosaurs, which had (and have) a
cosmopolitan distribution, to be found in the polar regions.

Re: Polar dinosaurs

<8f6dnf16XP6co0v9nZ2dnUU7-amdnZ2d@giganews.com>

 copy mid

https://www.novabbs.com/tech/article-flat.php?id=3135&group=sci.bio.paleontology#3135

 copy link   Newsgroups: sci.bio.paleontology
Path: i2pn2.org!i2pn.org!weretis.net!feeder8.news.weretis.net!feeds.phibee-telecom.net!newsfeed.xs4all.nl!newsfeed8.news.xs4all.nl!tr1.eu1.usenetexpress.com!feeder.usenetexpress.com!tr2.iad1.usenetexpress.com!border1.nntp.dca1.giganews.com!nntp.giganews.com!buffer1.nntp.dca1.giganews.com!buffer2.nntp.dca1.giganews.com!news.giganews.com.POSTED!not-for-mail
NNTP-Posting-Date: Fri, 25 Jun 2021 15:35:13 -0500
Subject: Re: Polar dinosaurs
Newsgroups: sci.bio.paleontology
References: <O42dnU2Z6Zi7Rkj9nZ2dnUU7-dHNnZ2d@giganews.com> <sb5672$j7q$1@solani.org>
From: jharsh...@pacbell.net (John Harshman)
Date: Fri, 25 Jun 2021 13:35:13 -0700
User-Agent: Mozilla/5.0 (Macintosh; Intel Mac OS X 10.15; rv:78.0) Gecko/20100101 Thunderbird/78.11.0
MIME-Version: 1.0
In-Reply-To: <sb5672$j7q$1@solani.org>
Content-Type: text/plain; charset=utf-8; format=flowed
Content-Language: en-US
Content-Transfer-Encoding: 8bit
Message-ID: <8f6dnf16XP6co0v9nZ2dnUU7-amdnZ2d@giganews.com>
Lines: 47
X-Usenet-Provider: http://www.giganews.com
X-Trace: sv3-rXeDdwyMfUw1smxDfdCKvrf/v4byFRWE6q9j1yMVYddX4D8byATgFJe3FIk931R7c0viN84F3XfCvrR!h5nmyNCLEaWY4ueJItFRdPKhOWEYeolKlGWChh6sMjEkuOaPZo4yHRq76B096y/fUDCeZk3B/n8=
X-Complaints-To: abuse@giganews.com
X-DMCA-Notifications: http://www.giganews.com/info/dmca.html
X-Abuse-and-DMCA-Info: Please be sure to forward a copy of ALL headers
X-Abuse-and-DMCA-Info: Otherwise we will be unable to process your complaint properly
X-Postfilter: 1.3.40
X-Original-Bytes: 4051
 by: John Harshman - Fri, 25 Jun 2021 20:35 UTC

On 6/25/21 11:10 AM, Oxyaena wrote:
> On 6/25/2021 9:33 AM, John Harshman wrote:
>> Here's the currently hot (pun unintended) news on dinosaurs at the poles:
>>
>> https://www.cell.com/current-biology/fulltext/S0960-9822(21)00739-9
>>
>> Fossils of the young of many species, good evidence that they nested
>> there, which is interpreted as evidence that they lived there
>> year-round, interpreted as further evidence of endothermy. There are
>> tyrannosaurids, hadrosaurs, ceratopsians, dromaeosaurs, and perhaps
>> pachycephalosaurs.
>>
>> Here's the abstract (called "summary", but potato potahto):
>>
>> "The unexpected discovery of non-avian dinosaurs from Arctic and
>> Antarctic settings has generated considerable debate about whether
>> they had the capacity to reproduce at high latitudes—especially the
>> larger-bodied, hypothetically migratory taxa. Evidence for dinosaurian
>> polar reproduction remains very rare, particularly for species that
>> lived at the highest paleolatitudes (>75°). Here we report the
>> discovery of perinatal and very young dinosaurs from the highest known
>> paleolatitude for the clade—the Cretaceous Prince Creek Formation
>> (PCF) of northern Alaska. These data demonstrate Arctic reproduction
>> in a diverse assemblage of large- and small-bodied ornithischian and
>> theropod species. In terms of overall diversity, 70% of the known
>> dinosaurian families, as well as avialans (birds), in the PCF are
>> represented by perinatal individuals, the highest percentage for any
>> North American Cretaceous formation. These findings, coupled with
>> prolonged incubation periods, small neonate sizes, and short
>> reproductive windows suggest most, if not all, PCF dinosaurs were
>> nonmigratory year-round Arctic residents. Notably, we reconstruct an
>> annual chronology of reproductive events for the ornithischian
>> dinosaurs using refined paleoenvironmental/plant phenology data and
>> new insights into dinosaur incubation periods. Seasonal resource
>> limitations due to extended periods of winter darkness and freezing
>> temperatures placed severe constraints on dinosaurian reproduction,
>> development, and maintenance, suggesting these taxa showed
>> polar-specific life history strategies, including endothermy."
>
> *Cryolophosaurus* is one of those aforementioned polar dinosaurs. I'm
> surprised they consider the discovery of dinosaurs in the Arctic and
> Antarctic to be "surprising." The poles weren't always frosty
> wastelands, it'd make sense for dinosaurs, which had (and have) a
> cosmopolitan distribution, to be found in the polar regions.

It's not dinosaurs that are surprising to them. It's baby dinosaurs. And
the current discovery is closer to the paleopoles than previous ones.

Re: Polar dinosaurs

<1a947b2e-f7ec-439b-8c43-9c869513cf95n@googlegroups.com>

 copy mid

https://www.novabbs.com/tech/article-flat.php?id=3136&group=sci.bio.paleontology#3136

 copy link   Newsgroups: sci.bio.paleontology
X-Received: by 2002:a05:620a:1258:: with SMTP id a24mr14507743qkl.225.1624670559391;
Fri, 25 Jun 2021 18:22:39 -0700 (PDT)
X-Received: by 2002:a25:b903:: with SMTP id x3mr16859023ybj.82.1624670559159;
Fri, 25 Jun 2021 18:22:39 -0700 (PDT)
Path: i2pn2.org!i2pn.org!paganini.bofh.team!usenet.pasdenom.info!usenet-fr.net!proxad.net!feeder1-2.proxad.net!209.85.160.216.MISMATCH!news-out.google.com!nntp.google.com!postnews.google.com!google-groups.googlegroups.com!not-for-mail
Newsgroups: sci.bio.paleontology
Date: Fri, 25 Jun 2021 18:22:38 -0700 (PDT)
In-Reply-To: <O42dnU2Z6Zi7Rkj9nZ2dnUU7-dHNnZ2d@giganews.com>
Injection-Info: google-groups.googlegroups.com; posting-host=2601:192:4c80:22d0:9842:d295:9734:8cf8;
posting-account=Si1SKwoAAADpFF5n-E1OIJfy3ARZBlIl
NNTP-Posting-Host: 2601:192:4c80:22d0:9842:d295:9734:8cf8
References: <O42dnU2Z6Zi7Rkj9nZ2dnUU7-dHNnZ2d@giganews.com>
User-Agent: G2/1.0
MIME-Version: 1.0
Message-ID: <1a947b2e-f7ec-439b-8c43-9c869513cf95n@googlegroups.com>
Subject: Re: Polar dinosaurs
From: jte...@gmail.com (JTEM)
Injection-Date: Sat, 26 Jun 2021 01:22:39 +0000
Content-Type: text/plain; charset="UTF-8"
 by: JTEM - Sat, 26 Jun 2021 01:22 UTC

John Harshman wrote:

> year-round, interpreted as further evidence of endothermy.

https://www.theguardian.com/world/1998/dec/18/1

This is MAJOR old news... extremely old.

Alaska was warm enough to host large reptiles. New England today
can't manage that.

-- --

https://jtem.tumblr.com/post/654901912313921536

Re: Polar dinosaurs

<sb8da5$b9d$1@solani.org>

 copy mid

https://www.novabbs.com/tech/article-flat.php?id=3137&group=sci.bio.paleontology#3137

 copy link   Newsgroups: sci.bio.paleontology
Path: i2pn2.org!i2pn.org!weretis.net!feeder8.news.weretis.net!feeder5.news.weretis.net!news.solani.org!.POSTED!not-for-mail
From: oxya...@invalid.invalid (Oxyaena)
Newsgroups: sci.bio.paleontology
Subject: Re: Polar dinosaurs
Date: Sat, 26 Jun 2021 19:30:11 -0400
Message-ID: <sb8da5$b9d$1@solani.org>
References: <O42dnU2Z6Zi7Rkj9nZ2dnUU7-dHNnZ2d@giganews.com>
<sb5672$j7q$1@solani.org> <8f6dnf16XP6co0v9nZ2dnUU7-amdnZ2d@giganews.com>
Mime-Version: 1.0
Content-Type: text/plain; charset=utf-8; format=flowed
Content-Transfer-Encoding: 8bit
Injection-Date: Sat, 26 Jun 2021 23:30:13 -0000 (UTC)
Injection-Info: solani.org;
logging-data="11565"; mail-complaints-to="abuse@news.solani.org"
User-Agent: Mozilla/5.0 (Windows NT 10.0; Win64; x64; rv:78.0) Gecko/20100101
Thunderbird/78.11.0
Cancel-Lock: sha1:6MkC4KrFtiV80AaymYttnb8G5Ds=
X-User-ID: eJwFwQcBwDAMAzBKy7HbwsnlD2ESjMI6TtCx2DdRhcwVnyUV48DW5ou4l8cGRGss36dpUeLS1rC8HO3+AXwoFlk=
Content-Language: en-US
In-Reply-To: <8f6dnf16XP6co0v9nZ2dnUU7-amdnZ2d@giganews.com>
 by: Oxyaena - Sat, 26 Jun 2021 23:30 UTC

On 6/25/2021 4:35 PM, John Harshman wrote:
> On 6/25/21 11:10 AM, Oxyaena wrote:
>> On 6/25/2021 9:33 AM, John Harshman wrote:
>>> Here's the currently hot (pun unintended) news on dinosaurs at the
>>> poles:
>>>
>>> https://www.cell.com/current-biology/fulltext/S0960-9822(21)00739-9
>>>
>>> Fossils of the young of many species, good evidence that they nested
>>> there, which is interpreted as evidence that they lived there
>>> year-round, interpreted as further evidence of endothermy. There are
>>> tyrannosaurids, hadrosaurs, ceratopsians, dromaeosaurs, and perhaps
>>> pachycephalosaurs.
>>>
>>> Here's the abstract (called "summary", but potato potahto):
>>>
>>> "The unexpected discovery of non-avian dinosaurs from Arctic and
>>> Antarctic settings has generated considerable debate about whether
>>> they had the capacity to reproduce at high latitudes—especially the
>>> larger-bodied, hypothetically migratory taxa. Evidence for
>>> dinosaurian polar reproduction remains very rare, particularly for
>>> species that lived at the highest paleolatitudes (>75°). Here we
>>> report the discovery of perinatal and very young dinosaurs from the
>>> highest known paleolatitude for the clade—the Cretaceous Prince Creek
>>> Formation (PCF) of northern Alaska. These data demonstrate Arctic
>>> reproduction in a diverse assemblage of large- and small-bodied
>>> ornithischian and theropod species. In terms of overall diversity,
>>> 70% of the known dinosaurian families, as well as avialans (birds),
>>> in the PCF are represented by perinatal individuals, the highest
>>> percentage for any North American Cretaceous formation. These
>>> findings, coupled with prolonged incubation periods, small neonate
>>> sizes, and short reproductive windows suggest most, if not all, PCF
>>> dinosaurs were nonmigratory year-round Arctic residents. Notably, we
>>> reconstruct an annual chronology of reproductive events for the
>>> ornithischian dinosaurs using refined paleoenvironmental/plant
>>> phenology data and new insights into dinosaur incubation periods.
>>> Seasonal resource limitations due to extended periods of winter
>>> darkness and freezing temperatures placed severe constraints on
>>> dinosaurian reproduction, development, and maintenance, suggesting
>>> these taxa showed polar-specific life history strategies, including
>>> endothermy."
>>
>> *Cryolophosaurus* is one of those aforementioned polar dinosaurs. I'm
>> surprised they consider the discovery of dinosaurs in the Arctic and
>> Antarctic to be "surprising." The poles weren't always frosty
>> wastelands, it'd make sense for dinosaurs, which had (and have) a
>> cosmopolitan distribution, to be found in the polar regions.
>
> It's not dinosaurs that are surprising to them. It's baby dinosaurs. And
> the current discovery is closer to the paleopoles than previous ones.

Why is that surprising? *Coryphodon*, an Eocene pantodont, also lived
near the poles and was a year round resident.

Re: Polar dinosaurs

<sb8ded$og0$1@dont-email.me>

 copy mid

https://www.novabbs.com/tech/article-flat.php?id=3138&group=sci.bio.paleontology#3138

 copy link   Newsgroups: sci.bio.paleontology
Path: i2pn2.org!i2pn.org!eternal-september.org!reader02.eternal-september.org!.POSTED!not-for-mail
From: x...@troll.org (Trolidous)
Newsgroups: sci.bio.paleontology
Subject: Re: Polar dinosaurs
Date: Sat, 26 Jun 2021 16:32:29 -0700
Organization: A noiseless patient Spider
Lines: 41
Message-ID: <sb8ded$og0$1@dont-email.me>
References: <O42dnU2Z6Zi7Rkj9nZ2dnUU7-dHNnZ2d@giganews.com>
Reply-To: x@troll.org
Mime-Version: 1.0
Content-Type: text/plain; charset=utf-8; format=flowed
Content-Transfer-Encoding: 8bit
Injection-Date: Sat, 26 Jun 2021 23:32:29 -0000 (UTC)
Injection-Info: reader02.eternal-september.org; posting-host="783bdfb52a3e545676216ccd2f5a559a";
logging-data="25088"; mail-complaints-to="abuse@eternal-september.org"; posting-account="U2FsdGVkX1/BsnsYeWqnP8IouO98qS+9nxw9/jOFilU="
User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:68.0) Gecko/20100101
Thunderbird/68.10.0
Cancel-Lock: sha1:TmxdJP+a08UL02pRlz1HoDM4MeM=
In-Reply-To: <O42dnU2Z6Zi7Rkj9nZ2dnUU7-dHNnZ2d@giganews.com>
Content-Language: en-US
 by: Trolidous - Sat, 26 Jun 2021 23:32 UTC

On 6/25/21 6:33 AM, John Harshman wrote:
> Here's the currently hot (pun unintended) news on dinosaurs at the poles:
>
> https://www.cell.com/current-biology/fulltext/S0960-9822(21)00739-9
>
> Fossils of the young of many species, good evidence that they nested
> there, which is interpreted as evidence that they lived there
> year-round, interpreted as further evidence of endothermy. There are
> tyrannosaurids, hadrosaurs, ceratopsians, dromaeosaurs, and perhaps
> pachycephalosaurs.
>
> Here's the abstract (called "summary", but potato potahto):
>
> "The unexpected discovery of non-avian dinosaurs from Arctic and
> Antarctic settings has generated considerable debate about whether they
> had the capacity to reproduce at high latitudes—especially the
> larger-bodied, hypothetically migratory taxa. Evidence for dinosaurian
> polar reproduction remains very rare, particularly for species that
> lived at the highest paleolatitudes (>75°). Here we report the discovery
> of perinatal and very young dinosaurs from the highest known
> paleolatitude for the clade—the Cretaceous Prince Creek Formation (PCF)
> of northern Alaska. These data demonstrate Arctic reproduction in a
> diverse assemblage of large- and small-bodied ornithischian and theropod
> species. In terms of overall diversity, 70% of the known dinosaurian
> families, as well as avialans (birds), in the PCF are represented by
> perinatal individuals, the highest percentage for any North American
> Cretaceous formation. These findings, coupled with prolonged incubation
> periods, small neonate sizes, and short reproductive windows suggest
> most, if not all, PCF dinosaurs were nonmigratory year-round Arctic
> residents. Notably, we reconstruct an annual chronology of reproductive
> events for the ornithischian dinosaurs using refined
> paleoenvironmental/plant phenology data and new insights into dinosaur
> incubation periods. Seasonal resource limitations due to extended
> periods of winter darkness and freezing temperatures placed severe
> constraints on dinosaurian reproduction, development, and maintenance,
> suggesting these taxa showed polar-specific life history strategies,
> including endothermy."

So do lizards shiver when they are cold?

What about other reptiles?

Re: Polar dinosaurs

<sb8f2m$c4l$2@solani.org>

 copy mid

https://www.novabbs.com/tech/article-flat.php?id=3139&group=sci.bio.paleontology#3139

 copy link   Newsgroups: sci.bio.paleontology
Path: i2pn2.org!i2pn.org!weretis.net!feeder8.news.weretis.net!feeder5.news.weretis.net!news.solani.org!.POSTED!not-for-mail
From: oxya...@invalid.invalid (Oxyaena)
Newsgroups: sci.bio.paleontology
Subject: Re: Polar dinosaurs
Date: Sat, 26 Jun 2021 20:00:21 -0400
Message-ID: <sb8f2m$c4l$2@solani.org>
References: <O42dnU2Z6Zi7Rkj9nZ2dnUU7-dHNnZ2d@giganews.com>
<sb8ded$og0$1@dont-email.me>
Mime-Version: 1.0
Content-Type: text/plain; charset=utf-8; format=flowed
Content-Transfer-Encoding: 8bit
Injection-Date: Sun, 27 Jun 2021 00:00:22 -0000 (UTC)
Injection-Info: solani.org;
logging-data="12437"; mail-complaints-to="abuse@news.solani.org"
User-Agent: Mozilla/5.0 (Windows NT 10.0; Win64; x64; rv:78.0) Gecko/20100101
Thunderbird/78.11.0
Cancel-Lock: sha1:xad/bliEafdB4xrTmhOrmAEbT/c=
In-Reply-To: <sb8ded$og0$1@dont-email.me>
Content-Language: en-US
X-User-ID: eJwNycEBwEAEBMCWcHZFOY7ov4RkvoNDZYcTdCzWhkUNTdjBEzeqvAwUlztHxcsVwu53omElvSnVwcn/cz8sdBUb
 by: Oxyaena - Sun, 27 Jun 2021 00:00 UTC

On 6/26/2021 7:32 PM, Trolidous wrote:
> On 6/25/21 6:33 AM, John Harshman wrote:
>> Here's the currently hot (pun unintended) news on dinosaurs at the poles:
>>
>> https://www.cell.com/current-biology/fulltext/S0960-9822(21)00739-9
>>
>> Fossils of the young of many species, good evidence that they nested
>> there, which is interpreted as evidence that they lived there
>> year-round, interpreted as further evidence of endothermy. There are
>> tyrannosaurids, hadrosaurs, ceratopsians, dromaeosaurs, and perhaps
>> pachycephalosaurs.
>>
>> Here's the abstract (called "summary", but potato potahto):
>>
>> "The unexpected discovery of non-avian dinosaurs from Arctic and
>> Antarctic settings has generated considerable debate about whether
>> they had the capacity to reproduce at high latitudes—especially the
>> larger-bodied, hypothetically migratory taxa. Evidence for dinosaurian
>> polar reproduction remains very rare, particularly for species that
>> lived at the highest paleolatitudes (>75°). Here we report the
>> discovery of perinatal and very young dinosaurs from the highest known
>> paleolatitude for the clade—the Cretaceous Prince Creek Formation
>> (PCF) of northern Alaska. These data demonstrate Arctic reproduction
>> in a diverse assemblage of large- and small-bodied ornithischian and
>> theropod species. In terms of overall diversity, 70% of the known
>> dinosaurian families, as well as avialans (birds), in the PCF are
>> represented by perinatal individuals, the highest percentage for any
>> North American Cretaceous formation. These findings, coupled with
>> prolonged incubation periods, small neonate sizes, and short
>> reproductive windows suggest most, if not all, PCF dinosaurs were
>> nonmigratory year-round Arctic residents. Notably, we reconstruct an
>> annual chronology of reproductive events for the ornithischian
>> dinosaurs using refined paleoenvironmental/plant phenology data and
>> new insights into dinosaur incubation periods. Seasonal resource
>> limitations due to extended periods of winter darkness and freezing
>> temperatures placed severe constraints on dinosaurian reproduction,
>> development, and maintenance, suggesting these taxa showed
>> polar-specific life history strategies, including endothermy."
>
> So do lizards shiver when they are cold?

Lizards are ectotherms, so no. Dinosaurs however were endotherms, like
mammals, and so they would've shivered.

>
> What about other reptiles?

Birds shiver.

Re: Polar dinosaurs

<TI-dnVwvMtPtZUr9nZ2dnUU7-YmdnZ2d@giganews.com>

 copy mid

https://www.novabbs.com/tech/article-flat.php?id=3140&group=sci.bio.paleontology#3140

 copy link   Newsgroups: sci.bio.paleontology
Path: i2pn2.org!i2pn.org!weretis.net!feeder8.news.weretis.net!news.uzoreto.com!tr1.eu1.usenetexpress.com!feeder.usenetexpress.com!tr3.iad1.usenetexpress.com!border1.nntp.dca1.giganews.com!nntp.giganews.com!buffer1.nntp.dca1.giganews.com!news.giganews.com.POSTED!not-for-mail
NNTP-Posting-Date: Sat, 26 Jun 2021 23:02:56 -0500
Subject: Re: Polar dinosaurs
Newsgroups: sci.bio.paleontology
References: <O42dnU2Z6Zi7Rkj9nZ2dnUU7-dHNnZ2d@giganews.com> <sb5672$j7q$1@solani.org> <8f6dnf16XP6co0v9nZ2dnUU7-amdnZ2d@giganews.com> <sb8da5$b9d$1@solani.org>
From: jharsh...@pacbell.net (John Harshman)
Date: Sat, 26 Jun 2021 21:02:56 -0700
User-Agent: Mozilla/5.0 (Macintosh; Intel Mac OS X 10.15; rv:78.0) Gecko/20100101 Thunderbird/78.11.0
MIME-Version: 1.0
In-Reply-To: <sb8da5$b9d$1@solani.org>
Content-Type: text/plain; charset=utf-8; format=flowed
Content-Language: en-US
Content-Transfer-Encoding: 8bit
Message-ID: <TI-dnVwvMtPtZUr9nZ2dnUU7-YmdnZ2d@giganews.com>
Lines: 57
X-Usenet-Provider: http://www.giganews.com
X-Trace: sv3-Y7UhXoDchqVt6ZVkA0fnSMMCQe697JQdc5Lxa6DKFTRRkNeP4vEn5aJcVvBDuv0DydMpKfZjSkbkL8o!0AqXfcx89lJJXVUp019giTcxmZECtJ4FbxecJd+Dyc484FWjD7+xvL6plEs/ToDkWD0ujLZRT/c=
X-Complaints-To: abuse@giganews.com
X-DMCA-Notifications: http://www.giganews.com/info/dmca.html
X-Abuse-and-DMCA-Info: Please be sure to forward a copy of ALL headers
X-Abuse-and-DMCA-Info: Otherwise we will be unable to process your complaint properly
X-Postfilter: 1.3.40
X-Original-Bytes: 4529
 by: John Harshman - Sun, 27 Jun 2021 04:02 UTC

On 6/26/21 4:30 PM, Oxyaena wrote:
> On 6/25/2021 4:35 PM, John Harshman wrote:
>> On 6/25/21 11:10 AM, Oxyaena wrote:
>>> On 6/25/2021 9:33 AM, John Harshman wrote:
>>>> Here's the currently hot (pun unintended) news on dinosaurs at the
>>>> poles:
>>>>
>>>> https://www.cell.com/current-biology/fulltext/S0960-9822(21)00739-9
>>>>
>>>> Fossils of the young of many species, good evidence that they nested
>>>> there, which is interpreted as evidence that they lived there
>>>> year-round, interpreted as further evidence of endothermy. There are
>>>> tyrannosaurids, hadrosaurs, ceratopsians, dromaeosaurs, and perhaps
>>>> pachycephalosaurs.
>>>>
>>>> Here's the abstract (called "summary", but potato potahto):
>>>>
>>>> "The unexpected discovery of non-avian dinosaurs from Arctic and
>>>> Antarctic settings has generated considerable debate about whether
>>>> they had the capacity to reproduce at high latitudes—especially the
>>>> larger-bodied, hypothetically migratory taxa. Evidence for
>>>> dinosaurian polar reproduction remains very rare, particularly for
>>>> species that lived at the highest paleolatitudes (>75°). Here we
>>>> report the discovery of perinatal and very young dinosaurs from the
>>>> highest known paleolatitude for the clade—the Cretaceous Prince
>>>> Creek Formation (PCF) of northern Alaska. These data demonstrate
>>>> Arctic reproduction in a diverse assemblage of large- and
>>>> small-bodied ornithischian and theropod species. In terms of overall
>>>> diversity, 70% of the known dinosaurian families, as well as
>>>> avialans (birds), in the PCF are represented by perinatal
>>>> individuals, the highest percentage for any North American
>>>> Cretaceous formation. These findings, coupled with prolonged
>>>> incubation periods, small neonate sizes, and short reproductive
>>>> windows suggest most, if not all, PCF dinosaurs were nonmigratory
>>>> year-round Arctic residents. Notably, we reconstruct an annual
>>>> chronology of reproductive events for the ornithischian dinosaurs
>>>> using refined paleoenvironmental/plant phenology data and new
>>>> insights into dinosaur incubation periods. Seasonal resource
>>>> limitations due to extended periods of winter darkness and freezing
>>>> temperatures placed severe constraints on dinosaurian reproduction,
>>>> development, and maintenance, suggesting these taxa showed
>>>> polar-specific life history strategies, including endothermy."
>>>
>>> *Cryolophosaurus* is one of those aforementioned polar dinosaurs. I'm
>>> surprised they consider the discovery of dinosaurs in the Arctic and
>>> Antarctic to be "surprising." The poles weren't always frosty
>>> wastelands, it'd make sense for dinosaurs, which had (and have) a
>>> cosmopolitan distribution, to be found in the polar regions.
>>
>> It's not dinosaurs that are surprising to them. It's baby dinosaurs.
>> And the current discovery is closer to the paleopoles than previous ones.
>
> Why is that surprising? *Coryphodon*, an Eocene pantodont, also lived
> near the poles and was a year round resident.

Because it's a mammal and it's Eocene. There was a big warming in the
Eocene.

Re: Polar dinosaurs

<sbeh93$h4g$1@dont-email.me>

 copy mid

https://www.novabbs.com/tech/article-flat.php?id=3141&group=sci.bio.paleontology#3141

 copy link   Newsgroups: sci.bio.paleontology
Path: i2pn2.org!i2pn.org!eternal-september.org!reader02.eternal-september.org!.POSTED!not-for-mail
From: x...@troll.org (Trolidous)
Newsgroups: sci.bio.paleontology
Subject: Re: Polar dinosaurs
Date: Tue, 29 Jun 2021 00:14:41 -0700
Organization: A noiseless patient Spider
Lines: 67
Message-ID: <sbeh93$h4g$1@dont-email.me>
References: <O42dnU2Z6Zi7Rkj9nZ2dnUU7-dHNnZ2d@giganews.com>
<sb8ded$og0$1@dont-email.me> <sb8f2m$c4l$2@solani.org>
Reply-To: x@troll.org
Mime-Version: 1.0
Content-Type: text/plain; charset=utf-8; format=flowed
Content-Transfer-Encoding: 8bit
Injection-Date: Tue, 29 Jun 2021 07:14:43 -0000 (UTC)
Injection-Info: reader02.eternal-september.org; posting-host="1e1be5d5ff56fba2d9653b853710bb95";
logging-data="17552"; mail-complaints-to="abuse@eternal-september.org"; posting-account="U2FsdGVkX19v8MywG6gfQUBW3m7kVBjEUIIEFukJqRU="
User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:68.0) Gecko/20100101
Thunderbird/68.10.0
Cancel-Lock: sha1:NQt2dGOUd5Jlr63fX5mjUJ4MYd8=
In-Reply-To: <sb8f2m$c4l$2@solani.org>
Content-Language: en-US
 by: Trolidous - Tue, 29 Jun 2021 07:14 UTC

On 6/26/21 5:00 PM, Oxyaena wrote:
> On 6/26/2021 7:32 PM, Trolidous wrote:
>> On 6/25/21 6:33 AM, John Harshman wrote:
>>> Here's the currently hot (pun unintended) news on dinosaurs at the
>>> poles:
>>>
>>> https://www.cell.com/current-biology/fulltext/S0960-9822(21)00739-9
>>>
>>> Fossils of the young of many species, good evidence that they nested
>>> there, which is interpreted as evidence that they lived there
>>> year-round, interpreted as further evidence of endothermy. There are
>>> tyrannosaurids, hadrosaurs, ceratopsians, dromaeosaurs, and perhaps
>>> pachycephalosaurs.
>>>
>>> Here's the abstract (called "summary", but potato potahto):
>>>
>>> "The unexpected discovery of non-avian dinosaurs from Arctic and
>>> Antarctic settings has generated considerable debate about whether
>>> they had the capacity to reproduce at high latitudes—especially the
>>> larger-bodied, hypothetically migratory taxa. Evidence for
>>> dinosaurian polar reproduction remains very rare, particularly for
>>> species that lived at the highest paleolatitudes (>75°). Here we
>>> report the discovery of perinatal and very young dinosaurs from the
>>> highest known paleolatitude for the clade—the Cretaceous Prince Creek
>>> Formation (PCF) of northern Alaska. These data demonstrate Arctic
>>> reproduction in a diverse assemblage of large- and small-bodied
>>> ornithischian and theropod species. In terms of overall diversity,
>>> 70% of the known dinosaurian families, as well as avialans (birds),
>>> in the PCF are represented by perinatal individuals, the highest
>>> percentage for any North American Cretaceous formation. These
>>> findings, coupled with prolonged incubation periods, small neonate
>>> sizes, and short reproductive windows suggest most, if not all, PCF
>>> dinosaurs were nonmigratory year-round Arctic residents. Notably, we
>>> reconstruct an annual chronology of reproductive events for the
>>> ornithischian dinosaurs using refined paleoenvironmental/plant
>>> phenology data and new insights into dinosaur incubation periods.
>>> Seasonal resource limitations due to extended periods of winter
>>> darkness and freezing temperatures placed severe constraints on
>>> dinosaurian reproduction, development, and maintenance, suggesting
>>> these taxa showed polar-specific life history strategies, including
>>> endothermy."
>>
>> So do lizards shiver when they are cold?
>
> Lizards are ectotherms, so no. Dinosaurs however were endotherms, like
> mammals, and so they would've shivered.

Do you have any references? Have you verified this?

Muscles are not one hundered percent efficient when
it comes to the conversion of chemical energy into
movement, and so exertion as well as brown fat does produce
heat.

So if an animal in winter does get near to freezing
point and it does not have frost resistance in its
tissues one way of surviving might be to burrow further
down into heat insulating soil, but as a short term
solution shivering might raise temperature enough to
avoid freezing. That is, if the nervous system is able
to detect when body temperature has dropped low enough
that there is danger of freezing.

There are some reptiles that live in places where there
is freezing in winter, like southern Canada. Maintaining
body heat within a narrow range is different from strategies
for avoiding freezing.

Re: Polar dinosaurs

<sbj5q3$isg$1@solani.org>

 copy mid

https://www.novabbs.com/tech/article-flat.php?id=3143&group=sci.bio.paleontology#3143

 copy link   Newsgroups: sci.bio.paleontology
Path: i2pn2.org!i2pn.org!weretis.net!feeder8.news.weretis.net!feeder5.news.weretis.net!news.solani.org!.POSTED!not-for-mail
From: oxya...@invalid.invalid (Oxyaena)
Newsgroups: sci.bio.paleontology
Subject: Re: Polar dinosaurs
Date: Wed, 30 Jun 2021 21:29:37 -0400
Message-ID: <sbj5q3$isg$1@solani.org>
References: <O42dnU2Z6Zi7Rkj9nZ2dnUU7-dHNnZ2d@giganews.com>
<sb8ded$og0$1@dont-email.me> <sb8f2m$c4l$2@solani.org>
<sbeh93$h4g$1@dont-email.me>
Mime-Version: 1.0
Content-Type: text/plain; charset=utf-8; format=flowed
Content-Transfer-Encoding: 8bit
Injection-Date: Thu, 1 Jul 2021 01:29:39 -0000 (UTC)
Injection-Info: solani.org;
logging-data="19344"; mail-complaints-to="abuse@news.solani.org"
User-Agent: Mozilla/5.0 (Windows NT 10.0; Win64; x64; rv:78.0) Gecko/20100101
Thunderbird/78.11.0
X-User-ID: eJwFwQERACAIA8BKThgccVBc/wj+0wJx04PhFGWvj1dlXi5v1QIeQ1cC5SPnJJHWydTBgXHvqtrtM4/zAVKUFXM=
In-Reply-To: <sbeh93$h4g$1@dont-email.me>
Cancel-Lock: sha1:cHn+ujwxKkHUQ26fQ+DfVG8y96o=
Content-Language: en-US
 by: Oxyaena - Thu, 1 Jul 2021 01:29 UTC

On 6/29/2021 3:14 AM, Trolidous wrote:
> On 6/26/21 5:00 PM, Oxyaena wrote:
>> On 6/26/2021 7:32 PM, Trolidous wrote:
>>> On 6/25/21 6:33 AM, John Harshman wrote:
>>>> Here's the currently hot (pun unintended) news on dinosaurs at the
>>>> poles:
>>>>
>>>> https://www.cell.com/current-biology/fulltext/S0960-9822(21)00739-9
>>>>
>>>> Fossils of the young of many species, good evidence that they nested
>>>> there, which is interpreted as evidence that they lived there
>>>> year-round, interpreted as further evidence of endothermy. There are
>>>> tyrannosaurids, hadrosaurs, ceratopsians, dromaeosaurs, and perhaps
>>>> pachycephalosaurs.
>>>>
>>>> Here's the abstract (called "summary", but potato potahto):
>>>>
>>>> "The unexpected discovery of non-avian dinosaurs from Arctic and
>>>> Antarctic settings has generated considerable debate about whether
>>>> they had the capacity to reproduce at high latitudes—especially the
>>>> larger-bodied, hypothetically migratory taxa. Evidence for
>>>> dinosaurian polar reproduction remains very rare, particularly for
>>>> species that lived at the highest paleolatitudes (>75°). Here we
>>>> report the discovery of perinatal and very young dinosaurs from the
>>>> highest known paleolatitude for the clade—the Cretaceous Prince
>>>> Creek Formation (PCF) of northern Alaska. These data demonstrate
>>>> Arctic reproduction in a diverse assemblage of large- and
>>>> small-bodied ornithischian and theropod species. In terms of overall
>>>> diversity, 70% of the known dinosaurian families, as well as
>>>> avialans (birds), in the PCF are represented by perinatal
>>>> individuals, the highest percentage for any North American
>>>> Cretaceous formation. These findings, coupled with prolonged
>>>> incubation periods, small neonate sizes, and short reproductive
>>>> windows suggest most, if not all, PCF dinosaurs were nonmigratory
>>>> year-round Arctic residents. Notably, we reconstruct an annual
>>>> chronology of reproductive events for the ornithischian dinosaurs
>>>> using refined paleoenvironmental/plant phenology data and new
>>>> insights into dinosaur incubation periods. Seasonal resource
>>>> limitations due to extended periods of winter darkness and freezing
>>>> temperatures placed severe constraints on dinosaurian reproduction,
>>>> development, and maintenance, suggesting these taxa showed
>>>> polar-specific life history strategies, including endothermy."
>>>
>>> So do lizards shiver when they are cold?
>>
>> Lizards are ectotherms, so no. Dinosaurs however were endotherms, like
>> mammals, and so they would've shivered.
>
> Do you have any references?  Have you verified this?

http://libgen.rs/fiction/8713E83994CA2B0BCE8ABA7A3B7451E5

The link in question is "The Dinosaur Heresies" by Robert T Bakker. It's
a bit dated, having been written in 1987 I believe, but it presents a
compelling case for dinosaur endothermy and helped kickstart a paradigm
shift when it comes to how we view dinosaurs.

>
> Muscles are not one hundered percent efficient when
> it comes to the conversion of chemical energy into
> movement, and so exertion as well as brown fat does produce
> heat.
>
> So if an animal in winter does get near to freezing
> point and it does not have frost resistance in its
> tissues one way of surviving might be to burrow further
> down into heat insulating soil, but as a short term
> solution shivering might raise temperature enough to
> avoid freezing.  That is, if the nervous system is able
> to detect when body temperature has dropped low enough
> that there is danger of freezing.
>
> There are some reptiles that live in places where there
> is freezing in winter, like southern Canada.  Maintaining
> body heat within a narrow range is different from strategies
> for avoiding freezing.

Re: Polar dinosaurs

<sbl8rp$s7a$1@dont-email.me>

 copy mid

https://www.novabbs.com/tech/article-flat.php?id=3144&group=sci.bio.paleontology#3144

 copy link   Newsgroups: sci.bio.paleontology
Path: i2pn2.org!i2pn.org!eternal-september.org!reader02.eternal-september.org!.POSTED!not-for-mail
From: x...@troll.org (Trolidous)
Newsgroups: sci.bio.paleontology
Subject: Re: Polar dinosaurs
Date: Thu, 1 Jul 2021 13:33:59 -0700
Organization: A noiseless patient Spider
Lines: 143
Message-ID: <sbl8rp$s7a$1@dont-email.me>
References: <O42dnU2Z6Zi7Rkj9nZ2dnUU7-dHNnZ2d@giganews.com>
<sb8ded$og0$1@dont-email.me> <sb8f2m$c4l$2@solani.org>
<sbeh93$h4g$1@dont-email.me> <sbj5q3$isg$1@solani.org>
Reply-To: x@troll.org
Mime-Version: 1.0
Content-Type: text/plain; charset=utf-8; format=flowed
Content-Transfer-Encoding: 8bit
Injection-Date: Thu, 1 Jul 2021 20:34:01 -0000 (UTC)
Injection-Info: reader02.eternal-september.org; posting-host="00018bd474412efb535a87e53d6d2480";
logging-data="28906"; mail-complaints-to="abuse@eternal-september.org"; posting-account="U2FsdGVkX1+SZZnZXtadVD4zCQyy1TlCDnOgjIvFYGU="
User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:68.0) Gecko/20100101
Thunderbird/68.10.0
Cancel-Lock: sha1:SADQwppzzboTzBPTP3EMfd3mZGI=
In-Reply-To: <sbj5q3$isg$1@solani.org>
Content-Language: en-US
 by: Trolidous - Thu, 1 Jul 2021 20:33 UTC

On 6/30/21 6:29 PM, Oxyaena wrote:
> On 6/29/2021 3:14 AM, Trolidous wrote:
>> On 6/26/21 5:00 PM, Oxyaena wrote:
>>> On 6/26/2021 7:32 PM, Trolidous wrote:
>>>> On 6/25/21 6:33 AM, John Harshman wrote:
>>>>> Here's the currently hot (pun unintended) news on dinosaurs at the
>>>>> poles:
>>>>>
>>>>> https://www.cell.com/current-biology/fulltext/S0960-9822(21)00739-9
>>>>>
>>>>> Fossils of the young of many species, good evidence that they
>>>>> nested there, which is interpreted as evidence that they lived
>>>>> there year-round, interpreted as further evidence of endothermy.
>>>>> There are tyrannosaurids, hadrosaurs, ceratopsians, dromaeosaurs,
>>>>> and perhaps pachycephalosaurs.
>>>>>
>>>>> Here's the abstract (called "summary", but potato potahto):
>>>>>
>>>>> "The unexpected discovery of non-avian dinosaurs from Arctic and
>>>>> Antarctic settings has generated considerable debate about whether
>>>>> they had the capacity to reproduce at high latitudes—especially the
>>>>> larger-bodied, hypothetically migratory taxa. Evidence for
>>>>> dinosaurian polar reproduction remains very rare, particularly for
>>>>> species that lived at the highest paleolatitudes (>75°). Here we
>>>>> report the discovery of perinatal and very young dinosaurs from the
>>>>> highest known paleolatitude for the clade—the Cretaceous Prince
>>>>> Creek Formation (PCF) of northern Alaska. These data demonstrate
>>>>> Arctic reproduction in a diverse assemblage of large- and
>>>>> small-bodied ornithischian and theropod species. In terms of
>>>>> overall diversity, 70% of the known dinosaurian families, as well
>>>>> as avialans (birds), in the PCF are represented by perinatal
>>>>> individuals, the highest percentage for any North American
>>>>> Cretaceous formation. These findings, coupled with prolonged
>>>>> incubation periods, small neonate sizes, and short reproductive
>>>>> windows suggest most, if not all, PCF dinosaurs were nonmigratory
>>>>> year-round Arctic residents. Notably, we reconstruct an annual
>>>>> chronology of reproductive events for the ornithischian dinosaurs
>>>>> using refined paleoenvironmental/plant phenology data and new
>>>>> insights into dinosaur incubation periods. Seasonal resource
>>>>> limitations due to extended periods of winter darkness and freezing
>>>>> temperatures placed severe constraints on dinosaurian reproduction,
>>>>> development, and maintenance, suggesting these taxa showed
>>>>> polar-specific life history strategies, including endothermy."
>>>>
>>>> So do lizards shiver when they are cold?
>>>
>>> Lizards are ectotherms, so no. Dinosaurs however were endotherms,
>>> like mammals, and so they would've shivered.
>>
>> Do you have any references?  Have you verified this?
>
> http://libgen.rs/fiction/8713E83994CA2B0BCE8ABA7A3B7451E5
>
> The link in question is "The Dinosaur Heresies" by Robert T Bakker. It's
> a bit dated, having been written in 1987 I believe, but it presents a
> compelling case for dinosaur endothermy and helped kickstart a paradigm
> shift when it comes to how we view dinosaurs.

Thank you for the link, however the term 'endotherm' and 'ectotherm'
has a lot of different variables thrown in with each other with
the terms that are actually separate and not obvious.

Some are - keeping a body temperature in a narrow range - how
narrow is it?

How hot or cold is that narrow range?

and then

Frost or freezing resistance - if that range can
go as low as near freezing - does the organism undergo
freezing - or can it move somewhere or adopt a strategy
at that low temperature to keep the body from freezing?

Now for plants you have some strategies for resisting
freezing, but they have limited energy resources because
they do not move around and gather energy from more locations
than where specific leaves were during the summer.

If plants use energy to keep their temperature warm through
an inefficient metabolic system producing heat the temperature
could then go way below freezing and overwhelm that strategy.

Do some plants do this? I do not know because it is not obvious
if someone has studied whether various species of plants keep
just one or two degrees above freezing by this strategy in a
frost. A light frost however is much different from extreme
cold.

Animals however have nervous systems and they can move.

For ectotherms however there is a first basic question. Can
their nervous systems and muscles still operate at 2 degrees
Celsius or maybe 35 degrees Farenheit? Can some different
species of reptiles do this but not others?

If they can do this then there is the question, can they
sense when body temperature has dropped to near freezing and
then do something else to keep warm enough to not freeze?

Well, one strategy might to build a good shelter or burrow
in autumn, and if it is not good enough then you may not
survive until spring unless you are like specific freeze
resistant amphibians at the bottom of lakes.

However there is the possibility that if a burrow gets
too cold a reptile might wake up and start digging deeper
to produce better insulation or to warm up slightly. Then
again, maybe it needed to produce a good burrow and if
it goes through something like hibernation it needed to
do something like that before winter started.

Either way the search terms 'ectotherm' or 'endotherm'
may not automatically come up with something that
specific, and it is not obvious to what extent research
might have been done on it. Wikipedia seems to have
the term 'mesotherm' and other 'therm' variants. A lot
of endotherms however generally tend to keep their body
temperature so far above freezing that starvation from
energy loss from heat production may be a much more
significant factor for warm blooded animals.

>>
>> Muscles are not one hundered percent efficient when
>> it comes to the conversion of chemical energy into
>> movement, and so exertion as well as brown fat does produce
>> heat.
>>
>> So if an animal in winter does get near to freezing
>> point and it does not have frost resistance in its
>> tissues one way of surviving might be to burrow further
>> down into heat insulating soil, but as a short term
>> solution shivering might raise temperature enough to
>> avoid freezing.  That is, if the nervous system is able
>> to detect when body temperature has dropped low enough
>> that there is danger of freezing.
>>
>> There are some reptiles that live in places where there
>> is freezing in winter, like southern Canada.  Maintaining
>> body heat within a narrow range is different from strategies
>> for avoiding freezing.
>

Re: Polar dinosaurs

<f7122143-70b5-41f0-b1f8-6c9ca7954cb0n@googlegroups.com>

 copy mid

https://www.novabbs.com/tech/article-flat.php?id=3145&group=sci.bio.paleontology#3145

 copy link   Newsgroups: sci.bio.paleontology
X-Received: by 2002:a05:620a:126e:: with SMTP id b14mr21917446qkl.36.1625608267072;
Tue, 06 Jul 2021 14:51:07 -0700 (PDT)
X-Received: by 2002:a25:3486:: with SMTP id b128mr30170765yba.523.1625608266889;
Tue, 06 Jul 2021 14:51:06 -0700 (PDT)
Path: i2pn2.org!i2pn.org!weretis.net!feeder6.news.weretis.net!news.snarked.org!border2.nntp.dca1.giganews.com!border1.nntp.dca1.giganews.com!nntp.giganews.com!news-out.google.com!nntp.google.com!postnews.google.com!google-groups.googlegroups.com!not-for-mail
Newsgroups: sci.bio.paleontology
Date: Tue, 6 Jul 2021 14:51:06 -0700 (PDT)
In-Reply-To: <sbl8rp$s7a$1@dont-email.me>
Injection-Info: google-groups.googlegroups.com; posting-host=2600:1700:48c9:290:bc80:43b7:9563:a85a;
posting-account=MmaSmwoAAABAWoWNw3B4MhJqLSp3_9Ze
NNTP-Posting-Host: 2600:1700:48c9:290:bc80:43b7:9563:a85a
References: <O42dnU2Z6Zi7Rkj9nZ2dnUU7-dHNnZ2d@giganews.com>
<sb8ded$og0$1@dont-email.me> <sb8f2m$c4l$2@solani.org> <sbeh93$h4g$1@dont-email.me>
<sbj5q3$isg$1@solani.org> <sbl8rp$s7a$1@dont-email.me>
User-Agent: G2/1.0
MIME-Version: 1.0
Message-ID: <f7122143-70b5-41f0-b1f8-6c9ca7954cb0n@googlegroups.com>
Subject: Re: Polar dinosaurs
From: peter2ny...@gmail.com (Peter Nyikos)
Injection-Date: Tue, 06 Jul 2021 21:51:07 +0000
Content-Type: text/plain; charset="UTF-8"
Content-Transfer-Encoding: quoted-printable
Lines: 231
 by: Peter Nyikos - Tue, 6 Jul 2021 21:51 UTC

Hi, Trolidus,

This may be my first direct reply to you, and I want to thank you for joining
sci.bio.paleontology. I hope you will hang around for many years.

On Thursday, July 1, 2021 at 4:34:03 PM UTC-4, Trolidous wrote:
> On 6/30/21 6:29 PM, Oxyaena wrote:
> > On 6/29/2021 3:14 AM, Trolidous wrote:
> >> On 6/26/21 5:00 PM, Oxyaena wrote:
> >>> On 6/26/2021 7:32 PM, Trolidous wrote:
> >>>> On 6/25/21 6:33 AM, John Harshman wrote:
> >>>>> Here's the currently hot (pun unintended) news on dinosaurs at the
> >>>>> poles:
> >>>>>
> >>>>> https://www.cell.com/current-biology/fulltext/S0960-9822(21)00739-9
> >>>>>
> >>>>> Fossils of the young of many species, good evidence that they
> >>>>> nested there, which is interpreted as evidence that they lived
> >>>>> there year-round, interpreted as further evidence of endothermy.
> >>>>> There are tyrannosaurids, hadrosaurs, ceratopsians, dromaeosaurs,
> >>>>> and perhaps pachycephalosaurs.
> >>>>>
> >>>>> Here's the abstract (called "summary", but potato potahto):
> >>>>>
> >>>>> "The unexpected discovery of non-avian dinosaurs from Arctic and
> >>>>> Antarctic settings has generated considerable debate about whether
> >>>>> they had the capacity to reproduce at high latitudes—especially the
> >>>>> larger-bodied, hypothetically migratory taxa. Evidence for
> >>>>> dinosaurian polar reproduction remains very rare, particularly for
> >>>>> species that lived at the highest paleolatitudes (>75°). Here we
> >>>>> report the discovery of perinatal and very young dinosaurs from the
> >>>>> highest known paleolatitude for the clade—the Cretaceous Prince
> >>>>> Creek Formation (PCF) of northern Alaska. These data demonstrate
> >>>>> Arctic reproduction in a diverse assemblage of large- and
> >>>>> small-bodied ornithischian and theropod species. In terms of
> >>>>> overall diversity, 70% of the known dinosaurian families, as well
> >>>>> as avialans (birds), in the PCF are represented by perinatal
> >>>>> individuals, the highest percentage for any North American
> >>>>> Cretaceous formation.

This is really remarkable, and goes far beyond the diversity I suspected until now.

> >>>>>These findings, coupled with prolonged
> >>>>> incubation periods, small neonate sizes, and short reproductive
> >>>>> windows suggest most, if not all, PCF dinosaurs were nonmigratory
> >>>>> year-round Arctic residents. Notably, we reconstruct an annual
> >>>>> chronology of reproductive events for the ornithischian dinosaurs
> >>>>> using refined paleoenvironmental/plant phenology data and new
> >>>>> insights into dinosaur incubation periods. Seasonal resource
> >>>>> limitations due to extended periods of winter darkness and freezing
> >>>>> temperatures placed severe constraints on dinosaurian reproduction,
> >>>>> development, and maintenance, suggesting these taxa showed
> >>>>> polar-specific life history strategies, including endothermy."
> >>>>
> >>>> So do lizards shiver when they are cold?
> >>>
> >>> Lizards are ectotherms, so no. Dinosaurs however were endotherms,
> >>> like mammals, and so they would've shivered.
> >>
> >> Do you have any references? Have you verified this?
> >
> > http://libgen.rs/fiction/8713E83994CA2B0BCE8ABA7A3B7451E5
> >
> > The link in question is "The Dinosaur Heresies" by Robert T Bakker. It's
> > a bit dated, having been written in 1987 I believe, but it presents a
> > compelling case for dinosaur endothermy and helped kickstart a paradigm
> > shift when it comes to how we view dinosaurs.

On the contrary, Bakker is a notorious popularizer who regularly goes out on limbs,
and the claim that ALL dinosaurs were endothermic is still very much up in the air.

On the other hand, some arguments for endothermy in at least some dinosaurs
go back to a 1969 paper by the great paleontologist, John Ostrom. His beliefs
on this evolved over time, to where he decided endothermy was largely restricted to theropods.

There have been some "outliers" in this debate, including Paul Sereno, Chenggang Rao,
and John Ruben, who have hypothesized that *Archaeopteryx* was an ectotherm..
Given the warm climate of the Late Jurassic, well above any seen in the last 5 million
years, this seems tenable. Also, see below about some surprising facts about modern birds.

> Thank you for the link, however the term 'endotherm' and 'ectotherm'
> has a lot of different variables thrown in with each other with
> the terms that are actually separate and not obvious.

In fact, the terms need to be supplemented by another: homeothermy. Its
chief merit is in the thesis that a large enough dinosaur could have maintained
a fairly stable body temperature throughout the day. This could have happened
in two ways: long storage of heat in the body of a large ectotherm, and the
"turning off" of endothermy when an endotherm attained a large enough size.

Jack Horner, a much more prolific researcher than Bakker, told me about
the latter possibility in a personal appearance at the South Carolina State Museum,
here in Columbia.

> Some are - keeping a body temperature in a narrow range - how
> narrow is it?
>
> How hot or cold is that narrow range?

There seems to be no one good answer. The situation is complicated by
many things, including the way there are intermediate conditions between
ectothermy and endothermy, as you yourself note later.

Even in some birds, there is a wide variation in daily body temperature:

"The well-known turkey vulture, (*Cathartes* *aura*) ... normally lowers its body temperature about at night 6 C (11 F) to 34 C (93 F) -- in other words, it becomes mildly hypothermic. Some small species with excessive surface exposure, such as hummingbirds (Trochilidae), are capable of entering a state of torpor, or profound hypothermia, in which they are unresponsive to most stimuli; their oxygen consumption can drop by some 75 percent when their body temperature drops by 10 C (18 F). By far the most dramatic example of torpor is exemplified by the common poorwills (*Phalaenoptilus* *nuttallii* : Caprimugiformes), which hibernate at a body temperature of 6 C [42.8 F] for up to two to three months during the winter; these birds normally require some seven hours to warm up."
-- Alan Feduccia, _Riddle_of_the_Feathered_Dragons, Yale University Press, 2012, p. 271.


> and then
>
> Frost or freezing resistance - if that range can
> go as low as near freezing - does the organism undergo
> freezing - or can it move somewhere or adopt a strategy
> at that low temperature to keep the body from freezing?
See above about poorwills!

<snip for the sake of brevity -- but only for the sake of brevity!>

> Animals however have nervous systems and they can move.
>
> For ectotherms however there is a first basic question. Can
> their nervous systems and muscles still operate at 2 degrees
> Celsius or maybe 35 degrees Farenheit? Can some different
> species of reptiles do this but not others?

Some arctic and antarctic fish are able to do this, obviously.
Stephen Jay Gould wrote something about this
in one of his essays; I'll try and look it up.

Peter Nyikos
Professor, Dept. of Mathematics -- standard disclaimer--
Univ. of South Carolina at Columbia
http://people.math.sc.edu/nyikos

PS you bring up some interesting possibilities below, which I don't know
enough about to comment on.

> If they can do this then there is the question, can they
> sense when body temperature has dropped to near freezing and
> then do something else to keep warm enough to not freeze?
>
> Well, one strategy might to build a good shelter or burrow
> in autumn, and if it is not good enough then you may not
> survive until spring unless you are like specific freeze
> resistant amphibians at the bottom of lakes.
>
> However there is the possibility that if a burrow gets
> too cold a reptile might wake up and start digging deeper
> to produce better insulation or to warm up slightly. Then
> again, maybe it needed to produce a good burrow and if
> it goes through something like hibernation it needed to
> do something like that before winter started.
>
> Either way the search terms 'ectotherm' or 'endotherm'
> may not automatically come up with something that
> specific, and it is not obvious to what extent research
> might have been done on it. Wikipedia seems to have
> the term 'mesotherm' and other 'therm' variants. A lot
> of endotherms however generally tend to keep their body
> temperature so far above freezing that starvation from
> energy loss from heat production may be a much more
> significant factor for warm blooded animals.
> >>
> >> Muscles are not one hundered percent efficient when
> >> it comes to the conversion of chemical energy into
> >> movement, and so exertion as well as brown fat does produce
> >> heat.
> >>
> >> So if an animal in winter does get near to freezing
> >> point and it does not have frost resistance in its
> >> tissues one way of surviving might be to burrow further
> >> down into heat insulating soil, but as a short term
> >> solution shivering might raise temperature enough to
> >> avoid freezing. That is, if the nervous system is able
> >> to detect when body temperature has dropped low enough
> >> that there is danger of freezing.
> >>
> >> There are some reptiles that live in places where there
> >> is freezing in winter, like southern Canada. Maintaining
> >> body heat within a narrow range is different from strategies
> >> for avoiding freezing.
> >


Click here to read the complete article
Re: Polar dinosaurs

<sccs2m$ot0$1@dont-email.me>

 copy mid

https://www.novabbs.com/tech/article-flat.php?id=3153&group=sci.bio.paleontology#3153

 copy link   Newsgroups: sci.bio.paleontology
Path: i2pn2.org!i2pn.org!eternal-september.org!reader02.eternal-september.org!.POSTED!not-for-mail
From: trolid...@go.com (Trolidous)
Newsgroups: sci.bio.paleontology
Subject: Re: Polar dinosaurs
Date: Sat, 10 Jul 2021 12:23:01 -0700
Organization: A noiseless patient Spider
Lines: 224
Message-ID: <sccs2m$ot0$1@dont-email.me>
References: <O42dnU2Z6Zi7Rkj9nZ2dnUU7-dHNnZ2d@giganews.com>
<sb8ded$og0$1@dont-email.me> <sb8f2m$c4l$2@solani.org>
<sbeh93$h4g$1@dont-email.me> <sbj5q3$isg$1@solani.org>
<sbl8rp$s7a$1@dont-email.me>
<f7122143-70b5-41f0-b1f8-6c9ca7954cb0n@googlegroups.com>
Mime-Version: 1.0
Content-Type: text/plain; charset=UTF-8; format=flowed
Content-Transfer-Encoding: 8bit
Injection-Date: Sat, 10 Jul 2021 19:23:02 -0000 (UTC)
Injection-Info: reader02.eternal-september.org; posting-host="c143983bc3290a2ba7424dd64e9f7f0e";
logging-data="25504"; mail-complaints-to="abuse@eternal-september.org"; posting-account="U2FsdGVkX19mXc693SamIhe4IMJMrw3UafuDWLCExRY="
User-Agent: Mozilla/5.0 (Windows NT 6.3; WOW64; rv:43.0) Gecko/20100101
Firefox/43.0 SeaMonkey/2.40
Cancel-Lock: sha1:TKuxiSZGIc9Vxn0Gc7tlWA04xZk=
In-Reply-To: <f7122143-70b5-41f0-b1f8-6c9ca7954cb0n@googlegroups.com>
 by: Trolidous - Sat, 10 Jul 2021 19:23 UTC

Peter Nyikos wrote:
> Hi, Trolidus,
>
> This may be my first direct reply to you, and I want to thank you for
joining
> sci.bio.paleontology. I hope you will hang around for many years.'

It is often difficult to know the future, however there are a lot
of interesting topics in biology.

> On Thursday, July 1, 2021 at 4:34:03 PM UTC-4, Trolidous wrote:
>> On 6/30/21 6:29 PM, Oxyaena wrote:
>>> On 6/29/2021 3:14 AM, Trolidous wrote:
>>>> On 6/26/21 5:00 PM, Oxyaena wrote:
>>>>> On 6/26/2021 7:32 PM, Trolidous wrote:
>>>>>> On 6/25/21 6:33 AM, John Harshman wrote:
>>>>>>> Here's the currently hot (pun unintended) news on dinosaurs at the
>>>>>>> poles:
>>>>>>>
>>>>>>> https://www.cell.com/current-biology/fulltext/S0960-9822(21)00739-9
>>>>>>>
>>>>>>> Fossils of the young of many species, good evidence that they
>>>>>>> nested there, which is interpreted as evidence that they lived
>>>>>>> there year-round, interpreted as further evidence of endothermy.
>>>>>>> There are tyrannosaurids, hadrosaurs, ceratopsians, dromaeosaurs,
>>>>>>> and perhaps pachycephalosaurs.
>>>>>>>
>>>>>>> Here's the abstract (called "summary", but potato potahto):
>>>>>>>
>>>>>>> "The unexpected discovery of non-avian dinosaurs from Arctic and
>>>>>>> Antarctic settings has generated considerable debate about whether
>>>>>>> they had the capacity to reproduce at high latitudes—especially the
>>>>>>> larger-bodied, hypothetically migratory taxa. Evidence for
>>>>>>> dinosaurian polar reproduction remains very rare, particularly for
>>>>>>> species that lived at the highest paleolatitudes (>75°). Here we
>>>>>>> report the discovery of perinatal and very young dinosaurs from the
>>>>>>> highest known paleolatitude for the clade—the Cretaceous Prince
>>>>>>> Creek Formation (PCF) of northern Alaska. These data demonstrate
>>>>>>> Arctic reproduction in a diverse assemblage of large- and
>>>>>>> small-bodied ornithischian and theropod species. In terms of
>>>>>>> overall diversity, 70% of the known dinosaurian families, as well
>>>>>>> as avialans (birds), in the PCF are represented by perinatal
>>>>>>> individuals, the highest percentage for any North American
>>>>>>> Cretaceous formation.
>
> This is really remarkable, and goes far beyond the diversity I
suspected until now.
>
>
>>>>>>> These findings, coupled with prolonged
>>>>>>> incubation periods, small neonate sizes, and short reproductive
>>>>>>> windows suggest most, if not all, PCF dinosaurs were nonmigratory
>>>>>>> year-round Arctic residents. Notably, we reconstruct an annual
>>>>>>> chronology of reproductive events for the ornithischian dinosaurs
>>>>>>> using refined paleoenvironmental/plant phenology data and new
>>>>>>> insights into dinosaur incubation periods. Seasonal resource
>>>>>>> limitations due to extended periods of winter darkness and freezing
>>>>>>> temperatures placed severe constraints on dinosaurian reproduction,
>>>>>>> development, and maintenance, suggesting these taxa showed
>>>>>>> polar-specific life history strategies, including endothermy."
>>>>>>
>>>>>> So do lizards shiver when they are cold?
>>>>>
>>>>> Lizards are ectotherms, so no. Dinosaurs however were endotherms,
>>>>> like mammals, and so they would've shivered.
>>>>
>>>> Do you have any references? Have you verified this?
>>>
>>> http://libgen.rs/fiction/8713E83994CA2B0BCE8ABA7A3B7451E5
>>>
>>> The link in question is "The Dinosaur Heresies" by Robert T Bakker.
It's
>>> a bit dated, having been written in 1987 I believe, but it presents a
>>> compelling case for dinosaur endothermy and helped kickstart a paradigm
>>> shift when it comes to how we view dinosaurs.
>
> On the contrary, Bakker is a notorious popularizer who regularly goes
out on limbs,
> and the claim that ALL dinosaurs were endothermic is still very much
up in the air.
>
> On the other hand, some arguments for endothermy in at least some
dinosaurs
> go back to a 1969 paper by the great paleontologist, John Ostrom. His
beliefs
> on this evolved over time, to where he decided endothermy was largely
restricted to theropods.
>
> There have been some "outliers" in this debate, including Paul
Sereno, Chenggang Rao,
> and John Ruben, who have hypothesized that *Archaeopteryx* was an
ectotherm.
> Given the warm climate of the Late Jurassic, well above any seen in
the last 5 million
> years, this seems tenable. Also, see below about some surprising
facts about modern birds.
>
>
>> Thank you for the link, however the term 'endotherm' and 'ectotherm'
>> has a lot of different variables thrown in with each other with
>> the terms that are actually separate and not obvious.
>
> In fact, the terms need to be supplemented by another: homeothermy. Its
> chief merit is in the thesis that a large enough dinosaur could have
maintained
> a fairly stable body temperature throughout the day. This could have
happened
> in two ways: long storage of heat in the body of a large ectotherm,
and the
> "turning off" of endothermy when an endotherm attained a large enough
size.
>
> Jack Horner, a much more prolific researcher than Bakker, told me about
> the latter possibility in a personal appearance at the South Carolina
State Museum,
> here in Columbia.
>
>
>> Some are - keeping a body temperature in a narrow range - how
>> narrow is it?
>>
>> How hot or cold is that narrow range?
>
> There seems to be no one good answer. The situation is complicated by
> many things, including the way there are intermediate conditions between
> ectothermy and endothermy, as you yourself note later.
>
> Even in some birds, there is a wide variation in daily body temperature:
>
> "The well-known turkey vulture, (*Cathartes* *aura*) ... normally
lowers its body temperature about at night 6 C (11 F) to 34 C (93 F) --
in other words, it becomes mildly hypothermic. Some small species with
excessive surface exposure, such as hummingbirds (Trochilidae), are
capable of entering a state of torpor, or profound hypothermia, in which
they are unresponsive to most stimuli; their oxygen consumption can drop
by some 75 percent when their body temperature drops by 10 C (18 F). By
far the most dramatic example of torpor is exemplified by the common
poorwills (*Phalaenoptilus* *nuttallii* : Caprimugiformes), which
hibernate at a body temperature of 6 C [42.8 F] for up to two to three
months during the winter; these birds normally require some seven hours
to warm up."
> -- Alan Feduccia, _Riddle_of_the_Feathered_Dragons, Yale University
Press, 2012, p. 271.
>
>
>> and then
>>
>> Frost or freezing resistance - if that range can
>> go as low as near freezing - does the organism undergo
>> freezing - or can it move somewhere or adopt a strategy
>> at that low temperature to keep the body from freezing?
>
> See above about poorwills!
>
>
> <snip for the sake of brevity -- but only for the sake of brevity!>
>
>
>> Animals however have nervous systems and they can move.
>>
>> For ectotherms however there is a first basic question. Can
>> their nervous systems and muscles still operate at 2 degrees
>> Celsius or maybe 35 degrees Farenheit? Can some different
>> species of reptiles do this but not others?
>
> Some arctic and antarctic fish are able to do this, obviously.
> Stephen Jay Gould wrote something about this
> in one of his essays; I'll try and look it up.
>
> Peter Nyikos
> Professor, Dept. of Mathematics -- standard disclaimer--
> Univ. of South Carolina at Columbia
> http://people.math.sc.edu/nyikos
>
> PS you bring up some interesting possibilities below, which I don't know
> enough about to comment on.
>
>
>> If they can do this then there is the question, can they
>> sense when body temperature has dropped to near freezing and
>> then do something else to keep warm enough to not freeze?
>>
>> Well, one strategy might to build a good shelter or burrow
>> in autumn, and if it is not good enough then you may not
>> survive until spring unless you are like specific freeze
>> resistant amphibians at the bottom of lakes.
>>
>> However there is the possibility that if a burrow gets
>> too cold a reptile might wake up and start digging deeper
>> to produce better insulation or to warm up slightly. Then
>> again, maybe it needed to produce a good burrow and if
>> it goes through something like hibernation it needed to
>> do something like that before winter started.
>>
>> Either way the search terms 'ectotherm' or 'endotherm'
>> may not automatically come up with something that
>> specific, and it is not obvious to what extent research
>> might have been done on it. Wikipedia seems to have
>> the term 'mesotherm' and other 'therm' variants. A lot
>> of endotherms however generally tend to keep their body
>> temperature so far above freezing that starvation from
>> energy loss from heat production may be a much more
>> significant factor for warm blooded animals.
>>>>
>>>> Muscles are not one hundered percent efficient when
>>>> it comes to the conversion of chemical energy into
>>>> movement, and so exertion as well as brown fat does produce
>>>> heat.
>>>>
>>>> So if an animal in winter does get near to freezing
>>>> point and it does not have frost resistance in its
>>>> tissues one way of surviving might be to burrow further
>>>> down into heat insulating soil, but as a short term
>>>> solution shivering might raise temperature enough to
>>>> avoid freezing. That is, if the nervous system is able
>>>> to detect when body temperature has dropped low enough
>>>> that there is danger of freezing.
>>>>
>>>> There are some reptiles that live in places where there
>>>> is freezing in winter, like southern Canada. Maintaining
>>>> body heat within a narrow range is different from strategies
>>>> for avoiding freezing.
>>>


Click here to read the complete article
Re: Polar dinosaurs

<009aff18-003b-4d48-b3ea-e228b93627ffn@googlegroups.com>

 copy mid

https://www.novabbs.com/tech/article-flat.php?id=3154&group=sci.bio.paleontology#3154

 copy link   Newsgroups: sci.bio.paleontology
X-Received: by 2002:ad4:4a03:: with SMTP id m3mr8130242qvz.33.1626226653744;
Tue, 13 Jul 2021 18:37:33 -0700 (PDT)
X-Received: by 2002:a25:720b:: with SMTP id n11mr10477417ybc.305.1626226653453;
Tue, 13 Jul 2021 18:37:33 -0700 (PDT)
Path: i2pn2.org!i2pn.org!weretis.net!feeder8.news.weretis.net!proxad.net!feeder1-2.proxad.net!209.85.160.216.MISMATCH!news-out.google.com!nntp.google.com!postnews.google.com!google-groups.googlegroups.com!not-for-mail
Newsgroups: sci.bio.paleontology
Date: Tue, 13 Jul 2021 18:37:33 -0700 (PDT)
In-Reply-To: <sccs2m$ot0$1@dont-email.me>
Injection-Info: google-groups.googlegroups.com; posting-host=2600:1700:48c9:290:29c2:e7da:f923:2447;
posting-account=MmaSmwoAAABAWoWNw3B4MhJqLSp3_9Ze
NNTP-Posting-Host: 2600:1700:48c9:290:29c2:e7da:f923:2447
References: <O42dnU2Z6Zi7Rkj9nZ2dnUU7-dHNnZ2d@giganews.com>
<sb8ded$og0$1@dont-email.me> <sb8f2m$c4l$2@solani.org> <sbeh93$h4g$1@dont-email.me>
<sbj5q3$isg$1@solani.org> <sbl8rp$s7a$1@dont-email.me> <f7122143-70b5-41f0-b1f8-6c9ca7954cb0n@googlegroups.com>
<sccs2m$ot0$1@dont-email.me>
User-Agent: G2/1.0
MIME-Version: 1.0
Message-ID: <009aff18-003b-4d48-b3ea-e228b93627ffn@googlegroups.com>
Subject: Re: Polar dinosaurs
From: peter2ny...@gmail.com (Peter Nyikos)
Injection-Date: Wed, 14 Jul 2021 01:37:33 +0000
Content-Type: text/plain; charset="UTF-8"
Content-Transfer-Encoding: quoted-printable
 by: Peter Nyikos - Wed, 14 Jul 2021 01:37 UTC

On Saturday, July 10, 2021 at 3:23:03 PM UTC-4, Trolidous wrote:
> Peter Nyikos wrote:
> > Hi, Trolidus,
> >
> > This may be my first direct reply to you, and I want to thank you for
> joining
> > sci.bio.paleontology. I hope you will hang around for many years.'
>
> It is often difficult to know the future, however there are a lot
> of interesting topics in biology.

There definitely are. Do you know of any worthwhile biology groups in the sci. category
besides this one and sci.anthropology.paleo?

I mourn the loss of sci.bio.evolution and sci.bio.systematics. The former was a great
group for a while but died over five years ago for lack of participation. The latter was not moderated
but seems to have suffered the same fate, perhaps much earlier. It still existed when I last looked,
but had been completely overrun by spammers.

I'll be starting a new thread early tomorrow on that fascinating Ediacaran enigma,
Dickinsonia. I had hoped to start it no later than today, but mathematical and family
obligations took up much more time than I expected.

I hope you can join it.

Peter Nyikos

> > On Thursday, July 1, 2021 at 4:34:03 PM UTC-4, Trolidous wrote:
> >> On 6/30/21 6:29 PM, Oxyaena wrote:
> >>> On 6/29/2021 3:14 AM, Trolidous wrote:
> >>>> On 6/26/21 5:00 PM, Oxyaena wrote:
> >>>>> On 6/26/2021 7:32 PM, Trolidous wrote:
> >>>>>> On 6/25/21 6:33 AM, John Harshman wrote:
> >>>>>>> Here's the currently hot (pun unintended) news on dinosaurs at the
> >>>>>>> poles:
> >>>>>>>
> >>>>>>> https://www.cell.com/current-biology/fulltext/S0960-9822(21)00739-9
> >>>>>>>
> >>>>>>> Fossils of the young of many species, good evidence that they
> >>>>>>> nested there, which is interpreted as evidence that they lived
> >>>>>>> there year-round, interpreted as further evidence of endothermy.
> >>>>>>> There are tyrannosaurids, hadrosaurs, ceratopsians, dromaeosaurs,
> >>>>>>> and perhaps pachycephalosaurs.
> >>>>>>>
> >>>>>>> Here's the abstract (called "summary", but potato potahto):
> >>>>>>>
> >>>>>>> "The unexpected discovery of non-avian dinosaurs from Arctic and
> >>>>>>> Antarctic settings has generated considerable debate about whether
> >>>>>>> they had the capacity to reproduce at high latitudes—especially the
> >>>>>>> larger-bodied, hypothetically migratory taxa. Evidence for
> >>>>>>> dinosaurian polar reproduction remains very rare, particularly for
> >>>>>>> species that lived at the highest paleolatitudes (>75°). Here we
> >>>>>>> report the discovery of perinatal and very young dinosaurs from the
> >>>>>>> highest known paleolatitude for the clade—the Cretaceous Prince
> >>>>>>> Creek Formation (PCF) of northern Alaska. These data demonstrate
> >>>>>>> Arctic reproduction in a diverse assemblage of large- and
> >>>>>>> small-bodied ornithischian and theropod species. In terms of
> >>>>>>> overall diversity, 70% of the known dinosaurian families, as well
> >>>>>>> as avialans (birds), in the PCF are represented by perinatal
> >>>>>>> individuals, the highest percentage for any North American
> >>>>>>> Cretaceous formation.
> >
> > This is really remarkable, and goes far beyond the diversity I
> suspected until now.
> >
> >
> >>>>>>> These findings, coupled with prolonged
> >>>>>>> incubation periods, small neonate sizes, and short reproductive
> >>>>>>> windows suggest most, if not all, PCF dinosaurs were nonmigratory
> >>>>>>> year-round Arctic residents. Notably, we reconstruct an annual
> >>>>>>> chronology of reproductive events for the ornithischian dinosaurs
> >>>>>>> using refined paleoenvironmental/plant phenology data and new
> >>>>>>> insights into dinosaur incubation periods. Seasonal resource
> >>>>>>> limitations due to extended periods of winter darkness and freezing
> >>>>>>> temperatures placed severe constraints on dinosaurian reproduction,
> >>>>>>> development, and maintenance, suggesting these taxa showed
> >>>>>>> polar-specific life history strategies, including endothermy."
> >>>>>>
> >>>>>> So do lizards shiver when they are cold?
> >>>>>
> >>>>> Lizards are ectotherms, so no. Dinosaurs however were endotherms,
> >>>>> like mammals, and so they would've shivered.
> >>>>
> >>>> Do you have any references? Have you verified this?
> >>>
> >>> http://libgen.rs/fiction/8713E83994CA2B0BCE8ABA7A3B7451E5
> >>>
> >>> The link in question is "The Dinosaur Heresies" by Robert T Bakker.
> It's
> >>> a bit dated, having been written in 1987 I believe, but it presents a
> >>> compelling case for dinosaur endothermy and helped kickstart a paradigm
> >>> shift when it comes to how we view dinosaurs.
> >
> > On the contrary, Bakker is a notorious popularizer who regularly goes
> out on limbs,
> > and the claim that ALL dinosaurs were endothermic is still very much
> up in the air.
> >
> > On the other hand, some arguments for endothermy in at least some
> dinosaurs
> > go back to a 1969 paper by the great paleontologist, John Ostrom. His
> beliefs
> > on this evolved over time, to where he decided endothermy was largely
> restricted to theropods.
> >
> > There have been some "outliers" in this debate, including Paul
> Sereno, Chenggang Rao,
> > and John Ruben, who have hypothesized that *Archaeopteryx* was an
> ectotherm.
> > Given the warm climate of the Late Jurassic, well above any seen in
> the last 5 million
> > years, this seems tenable. Also, see below about some surprising
> facts about modern birds.
> >
> >
> >> Thank you for the link, however the term 'endotherm' and 'ectotherm'
> >> has a lot of different variables thrown in with each other with
> >> the terms that are actually separate and not obvious.
> >
> > In fact, the terms need to be supplemented by another: homeothermy. Its
> > chief merit is in the thesis that a large enough dinosaur could have
> maintained
> > a fairly stable body temperature throughout the day. This could have
> happened
> > in two ways: long storage of heat in the body of a large ectotherm,
> and the
> > "turning off" of endothermy when an endotherm attained a large enough
> size.
> >
> > Jack Horner, a much more prolific researcher than Bakker, told me about
> > the latter possibility in a personal appearance at the South Carolina
> State Museum,
> > here in Columbia.
> >
> >
> >> Some are - keeping a body temperature in a narrow range - how
> >> narrow is it?
> >>
> >> How hot or cold is that narrow range?
> >
> > There seems to be no one good answer. The situation is complicated by
> > many things, including the way there are intermediate conditions between
> > ectothermy and endothermy, as you yourself note later.
> >
> > Even in some birds, there is a wide variation in daily body temperature:
> >
> > "The well-known turkey vulture, (*Cathartes* *aura*) ... normally
> lowers its body temperature about at night 6 C (11 F) to 34 C (93 F) --
> in other words, it becomes mildly hypothermic. Some small species with
> excessive surface exposure, such as hummingbirds (Trochilidae), are
> capable of entering a state of torpor, or profound hypothermia, in which
> they are unresponsive to most stimuli; their oxygen consumption can drop
> by some 75 percent when their body temperature drops by 10 C (18 F). By
> far the most dramatic example of torpor is exemplified by the common
> poorwills (*Phalaenoptilus* *nuttallii* : Caprimugiformes), which
> hibernate at a body temperature of 6 C [42.8 F] for up to two to three
> months during the winter; these birds normally require some seven hours
> to warm up."
> > -- Alan Feduccia, _Riddle_of_the_Feathered_Dragons, Yale University
> Press, 2012, p. 271.
> >
> >
> >> and then
> >>
> >> Frost or freezing resistance - if that range can
> >> go as low as near freezing - does the organism undergo
> >> freezing - or can it move somewhere or adopt a strategy
> >> at that low temperature to keep the body from freezing?
> >
> > See above about poorwills!
> >
> >
> > <snip for the sake of brevity -- but only for the sake of brevity!>
> >
> >
> >> Animals however have nervous systems and they can move.
> >>
> >> For ectotherms however there is a first basic question. Can
> >> their nervous systems and muscles still operate at 2 degrees
> >> Celsius or maybe 35 degrees Farenheit? Can some different
> >> species of reptiles do this but not others?
> >
> > Some arctic and antarctic fish are able to do this, obviously.
> > Stephen Jay Gould wrote something about this
> > in one of his essays; I'll try and look it up.
> >
> > Peter Nyikos
> > Professor, Dept. of Mathematics -- standard disclaimer--
> > Univ. of South Carolina at Columbia
> > http://people.math.sc.edu/nyikos
> >
> > PS you bring up some interesting possibilities below, which I don't know
> > enough about to comment on.
> >
> >
> >> If they can do this then there is the question, can they
> >> sense when body temperature has dropped to near freezing and
> >> then do something else to keep warm enough to not freeze?
> >>
> >> Well, one strategy might to build a good shelter or burrow
> >> in autumn, and if it is not good enough then you may not
> >> survive until spring unless you are like specific freeze
> >> resistant amphibians at the bottom of lakes.
> >>
> >> However there is the possibility that if a burrow gets
> >> too cold a reptile might wake up and start digging deeper
> >> to produce better insulation or to warm up slightly. Then
> >> again, maybe it needed to produce a good burrow and if
> >> it goes through something like hibernation it needed to
> >> do something like that before winter started.
> >>
> >> Either way the search terms 'ectotherm' or 'endotherm'
> >> may not automatically come up with something that
> >> specific, and it is not obvious to what extent research
> >> might have been done on it. Wikipedia seems to have
> >> the term 'mesotherm' and other 'therm' variants. A lot
> >> of endotherms however generally tend to keep their body
> >> temperature so far above freezing that starvation from
> >> energy loss from heat production may be a much more
> >> significant factor for warm blooded animals.
> >>>>
> >>>> Muscles are not one hundered percent efficient when
> >>>> it comes to the conversion of chemical energy into
> >>>> movement, and so exertion as well as brown fat does produce
> >>>> heat.
> >>>>
> >>>> So if an animal in winter does get near to freezing
> >>>> point and it does not have frost resistance in its
> >>>> tissues one way of surviving might be to burrow further
> >>>> down into heat insulating soil, but as a short term
> >>>> solution shivering might raise temperature enough to
> >>>> avoid freezing. That is, if the nervous system is able
> >>>> to detect when body temperature has dropped low enough
> >>>> that there is danger of freezing.
> >>>>
> >>>> There are some reptiles that live in places where there
> >>>> is freezing in winter, like southern Canada. Maintaining
> >>>> body heat within a narrow range is different from strategies
> >>>> for avoiding freezing.
> >>>


Click here to read the complete article
1
server_pubkey.txt

rocksolid light 0.9.7
clearnet tor