Nuclear preservation in the cartilage of the Jehol dinosaur
Caudipteryx

Abstract

Previous findings on dinosaur cartilage material from the Late
Cretaceous of Montana suggested that cartilage is a vertebrate tissue
with unique characteristics that favor nuclear preservation. Here, we
analyze additional dinosaur cartilage in Caudipteryx (STM4-3) from the
Early Cretaceous Jehol biota of Northeast China. The cartilage
fragment is highly diagenetically altered when observed in
ground-sections but shows exquisite preservation after
demineralization. It reveals transparent, alumino-silicified
chondrocytes and brown, ironized chondrocytes. The histochemical stain
Hematoxylin and Eosin (that stains the nucleus and cytoplasm in extant
cells) was applied to both the demineralized cartilage of Caudipteryx
and that of a chicken. The two specimens reacted identically, and one
dinosaur chondrocyte revealed a nucleus with fossilized threads of
chromatin. This is the second example of fossilized chromatin threads
in a vertebrate material. These data show that some of the original
nuclear biochemistry is preserved in this dinosaur cartilage material
and further support the hypothesis that cartilage is very prone to
nuclear fossilization and a perfect candidate to further understand
DNA preservation in deep time.

https://www.nature.com/articles/s42003-021-02627-8

On Saturday, September 25, 2021 at 7:57:18 AM UTC-7, Pandora wrote:
> Nuclear preservation in the cartilage of the Jehol dinosaur
> Caudipteryx
>
> Abstract
>
> Previous findings on dinosaur cartilage material from the Late
> Cretaceous of Montana suggested that cartilage is a vertebrate tissue
> with unique characteristics that favor nuclear preservation. Here, we
> analyze additional dinosaur cartilage in Caudipteryx (STM4-3) from the
> Early Cretaceous Jehol biota of Northeast China. The cartilage
> fragment is highly diagenetically altered when observed in
> ground-sections but shows exquisite preservation after
> demineralization. It reveals transparent, alumino-silicified
> chondrocytes and brown, ironized chondrocytes. The histochemical stain
> Hematoxylin and Eosin (that stains the nucleus and cytoplasm in extant
> cells) was applied to both the demineralized cartilage of Caudipteryx
> and that of a chicken. The two specimens reacted identically, and one
> dinosaur chondrocyte revealed a nucleus with fossilized threads of
> chromatin. This is the second example of fossilized chromatin threads
> in a vertebrate material. These data show that some of the original
> nuclear biochemistry is preserved in this dinosaur cartilage material
> and further support the hypothesis that cartilage is very prone to
> nuclear fossilization and a perfect candidate to further understand
> DNA preservation in deep time.
>
> https://www.nature.com/articles/s42003-021-02627-8

Very interesting result. The identical response to histochemical stains seen in Caudipteryx and
chicken is pretty amazing. Not Jurassic Park yet (just early Cretaceous), but getting closer. Have
to acknowedge Glenn's stupid but precient comment on another thread:

https://groups.google.com/g/sci.bio.paleontology/c/b83QxKc5qgY/m/j4QNkOOcAgAJ

On 9/25/21 7:57 AM, Pandora wrote:
> Nuclear preservation in the cartilage of the Jehol dinosaur
> Caudipteryx
>
> Abstract
>
> Previous findings on dinosaur cartilage material from the Late
> Cretaceous of Montana suggested that cartilage is a vertebrate tissue
> with unique characteristics that favor nuclear preservation. Here, we
> analyze additional dinosaur cartilage in Caudipteryx (STM4-3) from the
> Early Cretaceous Jehol biota of Northeast China. The cartilage
> fragment is highly diagenetically altered when observed in
> ground-sections but shows exquisite preservation after
> demineralization. It reveals transparent, alumino-silicified
> chondrocytes and brown, ironized chondrocytes. The histochemical stain
> Hematoxylin and Eosin (that stains the nucleus and cytoplasm in extant
> cells) was applied to both the demineralized cartilage of Caudipteryx
> and that of a chicken. The two specimens reacted identically, and one
> dinosaur chondrocyte revealed a nucleus with fossilized threads of
> chromatin. This is the second example of fossilized chromatin threads
> in a vertebrate material. These data show that some of the original
> nuclear biochemistry is preserved in this dinosaur cartilage material
> and further support the hypothesis that cartilage is very prone to
> nuclear fossilization and a perfect candidate to further understand
> DNA preservation in deep time.
>
> https://www.nature.com/articles/s42003-021-02627-8
>
I'm not optimistic that anything will come of this, but wouldn't it be
cool if it did?

On 9/25/2021 12:45 PM, John Harshman wrote:
> On 9/25/21 7:57 AM, Pandora wrote:
>> Nuclear preservation in the cartilage of the Jehol dinosaur
>> Caudipteryx
>>
>> Abstract
>>
>> Previous findings on dinosaur cartilage material from the Late
>> Cretaceous of Montana suggested that cartilage is a vertebrate tissue
>> with unique characteristics that favor nuclear preservation. Here, we
>> analyze additional dinosaur cartilage in Caudipteryx (STM4-3) from the
>> Early Cretaceous Jehol biota of Northeast China. The cartilage
>> fragment is highly diagenetically altered when observed in
>> ground-sections but shows exquisite preservation after
>> demineralization. It reveals transparent, alumino-silicified
>> chondrocytes and brown, ironized chondrocytes. The histochemical stain
>> Hematoxylin and Eosin (that stains the nucleus and cytoplasm in extant
>> cells) was applied to both the demineralized cartilage of Caudipteryx
>> and that of a chicken. The two specimens reacted identically, and one
>> dinosaur chondrocyte revealed a nucleus with fossilized threads of
>> chromatin. This is the second example of fossilized chromatin threads
>> in a vertebrate material. These data show that some of the original
>> nuclear biochemistry is preserved in this dinosaur cartilage material
>> and further support the hypothesis that cartilage is very prone to
>> nuclear fossilization and a perfect candidate to further understand
>> DNA preservation in deep time.
>>
>> https://www.nature.com/articles/s42003-021-02627-8
>>
> I'm not optimistic that anything will come of this, but wouldn't it be
> cool if it did?

That reminds me of the time they claimed to get viable DNA from some 40
million year old bug fossils found preserved in Amber. It's now thought
those results were due to carelessness, contamination, and several other
factors. In other words, they were inauthentic.

https://en.wikipedia.org/wiki/Ancient_DNA#1990s

The half-life of DNA is thought to be around 500 years old, so the
absolute upper limit for DNA recovery is around six million years or so.
Far too young to get anything meaningful from anything found in the
fossil of a non-avian dinosaur, that's for sure. Useful for the study of
human evolution, however.