#diapsids

[peregrinethegryphon]

Comparing Superficial Traits From Opposite Ends of the Sauropsid Family Tree Through a Visual Medium to Make a Point

~OR~

Birds Are Reptiles: The Gifset

Footage Sources: (x)(x)(x)(x)(x)(x)(x)

[agiantshark]

The recently described Middle Triassic Mirasaura grauvogeli might be small, but it is mighty up upon its tree stump

[mineralsrocksandfossiltalks]

Monday Musings: The Might of the Amniotic Egg

So far, we've learned about the earliest vertebrates and fishes and how one branch of those fishes grew legs and became the first amphibians but something even more amazing happened during the Carboniferous Period: the amniotic egg.

What is an amniotic egg? It is an egg that is adapted to retain water without needing to be in water. In other words, an egg with a shell (either soft or hard). Of course, just like living on land required more than just legs, amniotes (animals that produce an amnion) needed more than just a protective shell.

Fish and amphibians only have one inner membrane, the embryonic membrane. Amniotes have four: the yolk sac which surround the yolk, the amnion which surrounds and cushions the embryo, the allantois which helps with gas exchange and waste removal (becomes the umbilical cord in mammals) and the chorion which is the outer most membrane and surrounds everything.

Amniotes also lack otic notches because they are fully terrestrial (yes, some are secondarily aquatic but that is for a later discussion). Instead, they have extra holes in their heads for muscle attachments and to lighten the weight as amniotes can grow quite large.

Anapsids are the ancestral condition. These early amniotes lacked the temporal fenestrae that the other two groups have. Turtles are anapsids.

Synapsids have one set of lateral temporal fenestrae. Synapsids include mammals and their ancestors like us and Dimetrodon.

Diapsids have two sets of temporal fenestrae in their skulls. These include reptiles, dinosaurs and birds.

Other traits of amniotes include two pairs of sacral ribs (generally fused to the vertebra and the rest of the sacrum)

a sternum (some amniotes have lost this secondarily)

and an ankle bone called the astragalus.

Now that we know a little bit more about amniotes, tune in tomorrow for some trivia! Fossilize you later!

[readordiebyemilyt]

A new zine for summer kits!

[ianmalcolmptsd]

I’m still unsure which crime was more unforgivable: the existence of drepanosaurs in the first place, or their extinction meaning I can’t laugh at them to their faces now

[dragonthunders01]

Since I am always a fan of the size charts I decided to take a moment to scale each of the heads on the diapsid parade in relation to their proportions, several based on the size of the specimens that I used as a reference, and put where they are in the parade.

[rebelwithoutacause]

i already know you're a pisces but i would probably guess pisces anyway you just give off those vibes but i also feel like you've got a libra placement somewhere

this is my chart and i dont know what any of it means and i only see libra there twice lol

[worm-tv]

❤️

you have an EXCELLENT taste in music and your url is very good