With being bipedal, a pair of limbs is free to evolve further specializations towards grasping instead of walking. Yet for 150+ million years, no dinosaurs or dinosauromorph which was bipedal evolved hands that could pronate or have opposable thumbs.
There was even a pterosaur related to darwinopterus that evolved opposable thumbs.
However synapsids(primates and carnivorous especially) have evolved hands multiple times that can pronate and hold objects at least.
Why is that?
I know "more heterodont" is a misnomer, as you are either heterodont or homodont. But I think the wording illustrates the point of my question.
Synapsids, and especially Mammals are heterodont, they have clearly differentiated teeth: usually incisors, canines, premolars and molars. And that trend seems to have started with early Synapsids. However, what bugs me more is the extreme diversity of teeth that we find in them. Look at Mammals: we have rodents with square incisors that keep growing, elephants with also big tusks made from incisors, walrus with big tusks but made from canines, a lot of predators like cats and dogs with big fangs made from canines, even herbivores like the water deer with canine fangs, whatever the hell hippopothamus teeth are, lots of ruminants with grinding molars, Southamerican vampires with sharp fangs made out of incisors... you get my idea.
But when you go to Reptiles, sure there are a few Reptiles that really differentiated their teeth like some snake's fangs. Or Reptiles that don't possess teeth and have beaks instead like turtles and birds. I'm using the term "Reptiles" as monophyletic, that's why I'm including birds (assume I'm saying Diapsids instead of Reptiles). But even before the lineage that gave birds lost their teeth, those theropod dinosaurs were pretty homodont too. In any case, most Reptiles are homodont, they don't usually have differentiated teeth and they tend to have the same function.
Now I know things mutate randomly and if they are not strictly necessary, they are not necessarily favored by natural selection, therefore Reptiles are doing good enough with their low variety of teeth and I get that. However, why Mammals display so much variation between species unlike Reptiles in this particular case of teeth? Both Mammals and Reptiles have had to adapt to a lot of niches throughout the history of life, both have a lot of biodiversity and had to morphologically adapt a lot as an answer to their respective selective pressures, they all have evolved a lot. But when it comes to the variety of teeth between species within the same class, it seems it's mostly only Mammals that had experienced such variability. It's not just the heterodont condition within a single mouth what draws my attention, but that, in Mammals, when you go from species to species, there's a world of difference between them, like the examples I mentioned above (you go from rodents, to elephants, to bats, to primates, and it's all extremel
... keep reading on reddit β‘
I know this a bit of a weird/stupid question but they would probably need some long slongs unless they mated tail to tail. Anyways, what are your thoughts on this?
Also don't worry about them getting ideas, they probably can't read it unless it's in owo...
Like the were warm blooded right?
soβ¦.. what do you think if you evolved your own species of future βwarm bloodedβ reptiles (depending in species).
https://i.imgflip.com/5pyy61.jpg
I might be wrong and turtles are anapsids but as far as my knowledge goes, anapsids went extinct during the Permian-Triassic mass extinction.
How do you feel about feathered Sauropsids.
