In a time when dinosaurs and birds both co-existed how do they tell the difference between dinosaur feathers and bird feathers? What are the features of feathers between these species that differentiate them?
Well maybe. There were a class of very birdlike creatures called enantiornithines which I suspect are a completely different line and quite possibly not dinosaurs, however I've dug around before and am unable to find any precise statement of their genetic relationship to extant birds (and therefore their relationship to true dinosaurs).
"Enantiornitheans are thought to have left no living descendants ... the articulation of the shoulder bones – which has a concave-convex socket joint that is the reverse of that of modern birds"
It's in the article, along with photographs and CT scans:
"We can be sure of the source because the vertebrae are not fused into a rod or pygostyle as in modern birds and their closest relatives," he explained.
"Instead, the tail is long and flexible, with keels of feathers running down each side."
...
The feathers lack the well-developed central shaft - a rachis - known from modern birds. Their structure suggests that the two finest tiers of branching in modern feathers, known as barbs and barbules, arose before the rachis formed.
Restoring the full sequence is going to be like putting together a paper book that's been through a shredder.
And if you're thinking about cloning a dinosaur, that's even harder because you'd need to recreate exactly the same environment as in that specie's egg, otherwise the embryo won't survive to hatching. Not impossible, but extremely hard.
Restoring the full sequence of a proper sample after modern sequencing methods is already as convoluted as putting together a book after it's been through the shredder.
Restoring the full sequence of damaged DNA (any that's left) after millions of years is like trying to do the same after the shredder stuff has been burned
Impossible. DNA has an estimated half life of only 521 years [1]. It's a fairly reactive molecule due to the number of reactions it has to undergo to fulfill its purpose.
I believe the T-Rex soft tissue [2,3] that has been discovered contained short polypeptide sequences. You can infer the codons from this information, but that elides promotor, signaling, non-coding, etc regions that will be of massive importance. Not to mention you won't get much data in the first place.
Hundreds of years from now, any dinosaurs we recreate will be the result of creative genetic engineering and imagination.
Machine learning from what? Existing dinosaurs? The data is gone, what you're suggesting is that some type of AI is going to literally create life from nothing. Considering we aren't capable of autonomously driving a car down the road without killing someone, we've got a while to go before that happens.
> Considering we aren't capable of autonomously driving a car down the road without killing someone, we've got a while to go before that happens.
These two problems are completely unrelated. Also, every form of transportation can result in injury or death, even walking and bike riding, so setting our goal at 0 deaths as a benchmark for success doesn't make sense.
Feathers on a dinosaur make them a lot less scary IMO, even the one in the artist impression is kind of cute, but I know (if I was around) seeing a very toothy bird-like creature live and in person might make me change my mind.
I also had this with the Neanderthals paintings of Tom Bjørklund. Most of the time Neanderthals are rendered as ape like beings, but he draws them as humans. This made me think completely different about Neanderthals.
You (everyone) should study their skeletons. No different from ours, unless you are a forensic anthropologist. Especially considering the wide variety of human body shapes. Showing them as ape-like is a type of racism. Technically speciesism I suppose.
As others have commented modern birds of prey are pretty terrifying animals, majestic and beautiful, but they are large and terrifying. Even standing next to an ostrich (no teeth), its very hard to look past their general size and their 4 inch claws.
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[ 5.5 ms ] story [ 88.3 ms ] threadStill cool.
Enantiornithines had the wing joint inverted: https://en.wikipedia.org/wiki/Enantiornithes
"Enantiornitheans are thought to have left no living descendants ... the articulation of the shoulder bones – which has a concave-convex socket joint that is the reverse of that of modern birds"
If anyone can elucidate, please do.
At the bottom of the article is a link to another article on these creatures https://www.bbc.co.uk/news/science-environment-36651471 "Ancient birds' wings preserved in amber"
"We can be sure of the source because the vertebrae are not fused into a rod or pygostyle as in modern birds and their closest relatives," he explained.
"Instead, the tail is long and flexible, with keels of feathers running down each side."
...
The feathers lack the well-developed central shaft - a rachis - known from modern birds. Their structure suggests that the two finest tiers of branching in modern feathers, known as barbs and barbules, arose before the rachis formed.
And if you're thinking about cloning a dinosaur, that's even harder because you'd need to recreate exactly the same environment as in that specie's egg, otherwise the embryo won't survive to hatching. Not impossible, but extremely hard.
Restoring the full sequence of damaged DNA (any that's left) after millions of years is like trying to do the same after the shredder stuff has been burned
I believe the T-Rex soft tissue [2,3] that has been discovered contained short polypeptide sequences. You can infer the codons from this information, but that elides promotor, signaling, non-coding, etc regions that will be of massive importance. Not to mention you won't get much data in the first place.
Hundreds of years from now, any dinosaurs we recreate will be the result of creative genetic engineering and imagination.
[1] https://www.nature.com/news/dna-has-a-521-year-half-life-1.1...
[2] https://m.phys.org/news/2019-11-mechanisms-soft-tissue-prote...
[3] https://www.smithsonianmag.com/science-nature/dinosaur-shock...
Not to mention machine learning. I wonder if we get a bunch of samples from different individuals, could an AI simply just piece it all together?
I'm sure you could devise a "machine learning algorithm" that'll shove some random numbers in there, though.
Correct
> Considering we aren't capable of autonomously driving a car down the road without killing someone, we've got a while to go before that happens.
These two problems are completely unrelated. Also, every form of transportation can result in injury or death, even walking and bike riding, so setting our goal at 0 deaths as a benchmark for success doesn't make sense.
A list of his work: https://steemit.com/art/@cultureshock/these-neanderthal-char...
His website: https://www.tombjorklund.fi/
Instagram: https://www.instagram.com/tombjorklundart/