A 390 million-year-old hyper-compound eye in Devonian phacopid
trilobites

Abstract

Trilobites, extinct arthropods that dominated the faunas of the
Palaeozoic, since their appearance c 523 million years ago, were
equipped with elaborate compound eyes. While most of them possessed
apposition compound eyes (in trilobites called holochroal eyes),
comparable to the compound eyes of many diurnal crustaceans and
insects living today, trilobites of the suborder Phacopina developed
atypical large eyes with wide lenses and wide interspaces in between
(schizochroal eyes). Here, we show that these compound eyes are highly
sophisticated systems—hyper-compound eyes hiding an individual
compound eye below each of the big lenses. Thus, each of the phacopid
compound eyes comprises several tens, in cases even hundreds of small
compound eye systems composing a single visual surface. We discuss
their development, phylogenetic position of this hyper-compound eye,
and its neuronal infrastructure. A hyper-compound eye in this form is
unique in the animal realm.

Open access:
https://www.nature.com/articles/s41598-021-98740-z

On Thursday, September 30, 2021 at 8:04:26 AM UTC-7, Pandora wrote:
> A 390 million-year-old hyper-compound eye in Devonian phacopid
> trilobites
>
> Abstract
>
> Trilobites, extinct arthropods that dominated the faunas of the
> Palaeozoic, since their appearance c 523 million years ago, were
> equipped with elaborate compound eyes. While most of them possessed
> apposition compound eyes (in trilobites called holochroal eyes),
> comparable to the compound eyes of many diurnal crustaceans and
> insects living today, trilobites of the suborder Phacopina developed
> atypical large eyes with wide lenses and wide interspaces in between
> (schizochroal eyes). Here, we show that these compound eyes are highly
> sophisticated systems—hyper-compound eyes hiding an individual
> compound eye below each of the big lenses. Thus, each of the phacopid
> compound eyes comprises several tens, in cases even hundreds of small
> compound eye systems composing a single visual surface. We discuss
> their development, phylogenetic position of this hyper-compound eye,
> and its neuronal infrastructure. A hyper-compound eye in this form is
> unique in the animal realm.
>
> Open access:
> https://www.nature.com/articles/s41598-021-98740-z

That's neat! I've wondered for some time where the schizochroal eys came from, as
they seem to be a completely different design from previous trilobites eye. This result that
the big lens is superposed over the familiar compund eyes, eases that concern. (Easier to modify
something or add something to existing structures than completely replace.)

On Thursday, September 30, 2021 at 2:38:40 PM UTC-7, erik simpson wrote:
> On Thursday, September 30, 2021 at 8:04:26 AM UTC-7, Pandora wrote:
> > A 390 million-year-old hyper-compound eye in Devonian phacopid
> > trilobites
> >
> > Abstract
> >
> > Trilobites, extinct arthropods that dominated the faunas of the
> > Palaeozoic, since their appearance c 523 million years ago, were
> > equipped with elaborate compound eyes. While most of them possessed
> > apposition compound eyes (in trilobites called holochroal eyes),
> > comparable to the compound eyes of many diurnal crustaceans and
> > insects living today, trilobites of the suborder Phacopina developed
> > atypical large eyes with wide lenses and wide interspaces in between
> > (schizochroal eyes). Here, we show that these compound eyes are highly
> > sophisticated systems—hyper-compound eyes hiding an individual
> > compound eye below each of the big lenses. Thus, each of the phacopid
> > compound eyes comprises several tens, in cases even hundreds of small
> > compound eye systems composing a single visual surface. We discuss
> > their development, phylogenetic position of this hyper-compound eye,
> > and its neuronal infrastructure. A hyper-compound eye in this form is
> > unique in the animal realm.
> >
> > Open access:
> > https://www.nature.com/articles/s41598-021-98740-z
> That's neat! I've wondered for some time where the schizochroal eys came from, as
> they seem to be a completely different design from previous trilobites eye. This result that
> the big lens is superposed over the familiar compund eyes, eases that concern. (Easier to modify
> something or add something to existing structures than completely replace..)

Yea, you wouldn't want to add something that wasn't attached to an existing structure. But if this is an example of novelty, not modifying existing eyes or replacing them, why would you say that is easier than completely replacing them?

On Monday, October 4, 2021 at 7:33:01 PM UTC-7, Glenn wrote:
> On Thursday, September 30, 2021 at 2:38:40 PM UTC-7, erik simpson wrote:
> > On Thursday, September 30, 2021 at 8:04:26 AM UTC-7, Pandora wrote:
> > > A 390 million-year-old hyper-compound eye in Devonian phacopid
> > > trilobites
> > >
> > > Abstract
> > >
> > > Trilobites, extinct arthropods that dominated the faunas of the
> > > Palaeozoic, since their appearance c 523 million years ago, were
> > > equipped with elaborate compound eyes. While most of them possessed
> > > apposition compound eyes (in trilobites called holochroal eyes),
> > > comparable to the compound eyes of many diurnal crustaceans and
> > > insects living today, trilobites of the suborder Phacopina developed
> > > atypical large eyes with wide lenses and wide interspaces in between
> > > (schizochroal eyes). Here, we show that these compound eyes are highly
> > > sophisticated systems—hyper-compound eyes hiding an individual
> > > compound eye below each of the big lenses. Thus, each of the phacopid
> > > compound eyes comprises several tens, in cases even hundreds of small
> > > compound eye systems composing a single visual surface. We discuss
> > > their development, phylogenetic position of this hyper-compound eye,
> > > and its neuronal infrastructure. A hyper-compound eye in this form is
> > > unique in the animal realm.
> > >
> > > Open access:
> > > https://www.nature.com/articles/s41598-021-98740-z
> > That's neat! I've wondered for some time where the schizochroal eys came from, as
> > they seem to be a completely different design from previous trilobites eye. This result that
> > the big lens is superposed over the familiar compund eyes, eases that concern. (Easier to modify
> > something or add something to existing structures than completely replace.)
> Yea, you wouldn't want to add something that wasn't attached to an existing structure. But if this is an example of novelty, not modifying existing eyes or replacing them, why would you say that is easier than completely replacing them?

Try at least reading the abstract. If you'd like to learn more, try reading the article. (It's open source, at least for now.)

On Monday, October 4, 2021 at 9:38:10 PM UTC-7, erik simpson wrote:
> On Monday, October 4, 2021 at 7:33:01 PM UTC-7, Glenn wrote:
> > On Thursday, September 30, 2021 at 2:38:40 PM UTC-7, erik simpson wrote:
> > > On Thursday, September 30, 2021 at 8:04:26 AM UTC-7, Pandora wrote:
> > > > A 390 million-year-old hyper-compound eye in Devonian phacopid
> > > > trilobites
> > > >
> > > > Abstract
> > > >
> > > > Trilobites, extinct arthropods that dominated the faunas of the
> > > > Palaeozoic, since their appearance c 523 million years ago, were
> > > > equipped with elaborate compound eyes. While most of them possessed
> > > > apposition compound eyes (in trilobites called holochroal eyes),
> > > > comparable to the compound eyes of many diurnal crustaceans and
> > > > insects living today, trilobites of the suborder Phacopina developed
> > > > atypical large eyes with wide lenses and wide interspaces in between
> > > > (schizochroal eyes). Here, we show that these compound eyes are highly
> > > > sophisticated systems—hyper-compound eyes hiding an individual
> > > > compound eye below each of the big lenses. Thus, each of the phacopid
> > > > compound eyes comprises several tens, in cases even hundreds of small
> > > > compound eye systems composing a single visual surface. We discuss
> > > > their development, phylogenetic position of this hyper-compound eye,
> > > > and its neuronal infrastructure. A hyper-compound eye in this form is
> > > > unique in the animal realm.
> > > >
> > > > Open access:
> > > > https://www.nature.com/articles/s41598-021-98740-z
> > > That's neat! I've wondered for some time where the schizochroal eys came from, as
> > > they seem to be a completely different design from previous trilobites eye. This result that
> > > the big lens is superposed over the familiar compund eyes, eases that concern. (Easier to modify
> > > something or add something to existing structures than completely replace.)
> > Yea, you wouldn't want to add something that wasn't attached to an existing structure. But if this is an example of novelty, not modifying existing eyes or replacing them, why would you say that is easier than completely replacing them?
> Try at least reading the abstract. If you'd like to learn more, try reading the article. (It's open source, at least for now.)

Why, did you write that too?