#sauropterygian

[alex-fictus]

Henodus isn’t what you think they are!

Looking at them, they are spectacularly turtle-like, but they’re actually a Sauropterygian! This means they’re a closer relative to Plesiosaurs than to Testudine Turtles!

For a true turtle, look for Archelon, the mega turtle of the Cretaceous!

Sticker here || Wallpaper here!

[saritawolff]

Patreon request for rome.and.stuff (Instagram), and my first plesiosaur (well, first since I was like… 10)

Pliosaurus funkei!

Pliosaurs were a family of plesiosaurs that eventually lost their stereotypical long-necked, small-headed body plan. Resembling the mosasaurs that would come much later, pliosaurs had short necks with large, strong jaws, and fed on fish, cephalopods, and marine reptiles. The type genus, Pliosaurus, contains at least 6 species. The first and type species, P. brachydeirus, was described and named by Sir Richard Owen in 1841.

Between 2004 and 2012, a new species of Pliosaurus was in the process of being uncovered. Before it was formally described or even named, news of this giant sea monster escaped into the general media and it was dubbed “Predator X”.

This Predator X prompted a media frenzy… there were articles estimating its size based on the fragments found so far, a 2009 television special on the History channel, and a segment in the 2011 BBC documentary series “Planet Dinosaur.”

Predator X was reportedly the “most fearsome animal ever to swim in the oceans!”

When Pliosaurus funkei was finally formally described and named in 2012, it was found to be a bit smaller than the giant 15 meter long estimate being thrown around. However, it was still a very large animal, around 10–12 m (33��39 ft) long with a 2.0–2.5 m (6.6–8.2 ft) long skull. It also had very long flippers, probably to aid in maneuverability and speed. Analysis of Pliosaurus funkei’s skeleton show that it likely used its front flippers to cruise, only using its back flippers for quick bursts of speed when pursuing prey. Analysis of its brain case shows that its brain was proportional to that of a modern great white shark. So while it didn’t quite beat the Late Cretaceous 12–15.8 meter (39–52 ft) long mosasaur Tylosaurus, the Early Miocene to Late Pliocene 10.5-20.3 meter (34-67 ft) long shark Otodus megalodon, or even the modern day 11-16 meter (36-52 ft) long Physeter macrocephalus (Sperm Whale), it was still no doubt the apex predator of its time and environment.

Pliosaurus funkei lived in the last era of the Late Jurassic in the icy waters of Norway. Found in the Slottsmøya Member of the Agardhfjellet Formation, it would have lived in a cold, shallow sea rife with methane seeps. These methane seeps supported a high amount of diversity, and the Slottsmøya was teeming with ammonites, bivalves, gastropods, brachiopods, tubeworms, echinoderms, cold water sponges, and more. Many icthyosaurs and plesiosaurs would have enjoyed feeding on the plentiful invertebrates here, as well as each other. Pliosaurus funkei would have likely fed on other plesiosaurs like Colymbosaurus, Djupedalia, Ophthalmothule, and Spitrasaurus, as well as icthyosaurs like Cryopterygius, Undorosaurus, Arthropterygius, Nannopterygius, and Brachypterygius.

[a-dinosaur-a-day]

How closely related are marine reptiles like plesiosaurs and ichthyosaurs to dinosaurs? I know mosasaurs are more related to lizards but wasn’t sure about the other famous marine reptiles.

I know they’re not dinosaurs obviously but I was curious if it was a case of close relatives like pterosaurs. They don’t seem very close so I’m assuming not very related at all, and they’re just grouped in since they’re contemporary.

Soooo we don't know *how* close they are because their evolutionary relationships are in flux, but they aren't super close. Ichthyosaurs may not even be in crown-reptiles - ie, they aren't more closely related to dinosaurs or crocs or lizards, but equally closely related to all of them, falling outside the group that contains living reptiles. Or they're grouped with the other marine reptiles, called Sauropterygians. Sauropterygians includes plesiosaurs, pliosaurs, and a bunch of Triassic Weirdos. For a while, we thought they were closer to living turtles than anything else - so in Pan-Testudines. But that's come into question, especially now that we know turtles are part of the crocodile-bird tree (Archosauromorphs) than the lizard-snake tree. However, recent studies have indicated they may be Archosauromorphs.

So the short version of all that is: they may be closer to dinosaurs than to lizards, but they also might just be equally closely related to all living reptiles. Or maybe they're closer to turtles than to lizards or dinosaurs. Who knows. Science is fun!

[mariolanzas]

PLESIOSAURIA

This chart shows only some Plesiosaurs, featured on my latest video dedicated to Sauropterygians. You can see man more related animals there. This composition is now also available at REdbubble for Prints, T-Shirts and more

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[ofowlsdinosaursanddragons]

Wanted to do my own take on Scylla for the "Epic: The Musical"! For her design, I took inspiration from plesiosaurs like rhomaleosaurus along with the walking with dinosaurs’ Liopleurodon for an extra reference with both being massive sauropterygians.

[dragonthunders01]

Something that occurred to me on a discussion regarding bowhead whales and sauropterygians, it came to my mind to me to create the ultimate Aristonectid descendant, these pull out the extreme of filter feeding adaptation of their group turning their lower jaw into a specialized large set of baleen-like structures growing out of the gum, with a huge sloth that holds the keel of the palate so it push the water while it catch the food; they extremely developed their heads, coming out of a short necked and bigger head trend that started in the Paleogene, their heads now forms half of the body length, the upper teeth have become useless for feeding so they preserved them as a sort of defense helping them while ramming towards adversaries.

[mousegirlheart]

Plesiosaurs are not technically dinosaurs, but classified as a sauropterygian (flippered lizard) reptile, a type of non-saurian diapsid like ichthyosaurs and thalattosaurs. The reason why I know this is because my favorite ancient extinct reptile is the Liopleurodon ferox which is a type of pliosaurid (short-necked) plesiosaur, and my second favorite is the Stelladens mysteriosus, a mosasaur which is not related to plesiosaurs they are squamates like snakes.

my life is a lie...

[sinosauropteryx--prima]

Life in the Early Triassic

(first row: Sclerosaurus, Lystrosaurus; second row: Hupehsuchus, Triadobatrachus, Cartorhynchus; thrid row: Rebellatrix, Atopodentatus; fourth row: Aphaneramma, Erythrosuchus)

Lystrosaurus - Julio Lacerda

Erythrosuchus - Mark Witton

Rebellatrix - Michael Skrepnick

Aphaneramma - Gabriel Ugueto

Cartorhynchus, Hupehsuchus, Atopodentatus - Nobu Tamura

Triadobatrachus - Alexey Malitskiy

Sclerosaurus - Wikimedia

We‘ve reached the Triassic period and with it the Mesozoic Era, the Age of Reptiles! Right now (about 250 million years ago), the reptiles are not dominating yet - in fact no one really was doing too well, as the Early Triassic was mostly a recovery period with low diversity after the most devastating mass extinction of all time, The Great Dying, at the end of the Permian.

The one exception to this is Lystrosaurus. The pig-sized herbivores somehow made it through the mass extinction mostly unscathed and in a now barren world they re-diversified, took up empty niches and became the most common vertebrate in many areas. It is not entirely clear why they survived. Maybe it was hibernation or burrowing that gave them some kind of protection from the worst parts of The Great Dying, maybe they were just lucky. Whatever it was, these prehistoric cockroaches marked one of the last big hurrahs of the synapsids (our own linage), before they went into hiding and lived their lifes as rodent size critters in the shadows of the reptiles for the following 200 million years or so.

The synapsids were the stars of the Permian, but only three groups of them made it into the Triassic: The carnivorous therocephalians and the herbivorous dicynodonts like Lystrosaurus with bulky bodies, mostly toothless beaks and tusk-like canines. They both went extinct during the Triassic. A third group, the cynodonts, survived much longer and will eventually include all modern mammals, from the tiniest bats to the biggest whales. But right now all of that is just some distant future.

Right now, at the beginning of the Triassic, a lot of other groups hurry to fill empty spaces. Several groups of reptiles decided that, after their ancestors once spent a lot of time and effort to evolve a terrestrial lifestyle, they want to return to the oceans. This included early cousins of the ichthyosaurs (those dolphin-shaped marine reptiles that lived alongside the dinosaurs) like Cartorhynchus and very basal sauropterygians. The most famous member of that group are the Loch-Ness-Monster-looking plesiosaurs, but one early member was the strange Atopodentatus. They possibly used their weird mouths to eat algae, making them one of the earliest herbivorous marine reptiles.

On land, the most interesting development might be the rise of the archosaurs and their close relatives. Over the span of the Mesozoic, the age of reptiles, they became the dominate group of life including many fan-favorites: The giant dinosaurs, the flying pterosaurs, the birds we have today and the wide variety of crocs, both past and present. At the beginning of the Triassic, they are just starting out, but 5 m long predators like the big-headed Erythrosuchus (although they are technically not quite archosaurs), already give a glimpse into their future.

[skibidiartzz5]

Plesiosaurus is a genus of extinct, large marine sauropterygian reptile that lived during the Early Jurassic. It is known by nearly complete skeletons from the Lias of England. It is distinguishable by its small head, long and slender neck, broad turtle-like body, a short tail, and two pairs of large, elongated paddles. It lends its name to the order Plesiosauria, of which it is an early, but fairly typical member. It contains only one species, the type, Plesiosaurus dolichodeirus. Other species once assigned to this genus, including P. brachypterygius, P. guilielmiimperatoris, and P. tournemirensis have been reassigned to new genera, such as Hydrorion, Seeleyosaurus and Occitanosaurus

[Plesiosaurus dolichodeirus]

[moon-snailsss]

Plesiosaur

| the name plesiosaur is Greek for “almost lizard”

Lived 208.5 to 66 million years ago

They are sauropterygian (si-ro-pto-raey-gian) reptiles basically meaning they are aquatic reptiles

They lived during the early Jurassic period and when extinct during the Cretaceous period

They were carnivorous (they ate meat) mostly fish

Plesiosaurs had a bite force of 33 thousand psi (pound force per square inch)their neck could grow up to 7 meters (22 feet) long

[alex-fictus]

Plesiosaurus! Somehow this is the only plesiosaur I have in my shop, that will be updating soon! I have sketches for Nyxosaurus, Elasmosaurus, and Lindwurmia-- any you think I should add?

I also might redo this design, I've updated it since but I didn't draw the head correctly :( Get this sticker here!

[mineralsrocksandfossiltalks]

March Madness Day 2!

Mosasaurus

Or Elasmosaurus

So, why aren't yhese guys considered dinosaurs? Here's a few reasons:

1.) Both are marine organisms. Dinosaurs (at least non-avian) are terrestrial.

2.) Mosasaurus is a aquamate. Basically, a giant sea lizard.

Dinosaurs are archosaurs.

Elasmosaurus is a sauropterygian like Nothosaurus.

Which one do you want to keep in the competition? REBLOG for MOSASAURUS.

LIKE for ELASMOSAURUS.

Voting open until tier 2 begins (March 16).

[artapir]

Alt-Triassic crossbilled sauropterygian via Midjourney 5.1.

[a-dinosaur-a-day]

reptiles are the only TRUE genders

all of these clades can be found on the wikipedias

[mariolanzas]

NEW VIDEO!

Plesiosaurs and other Sauropterygians

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[dragonthunders01]

Spectember D25: Ontogenetic niche shifts

Earth has recovered from a mass extinction just about 30 million years ago which would correspond to the time of the Oligocene, this version of earth happened the mass extinction of the K/Pg was delayed, so instead of ending in 66 million years ago cretaceous continued for other 30 million years until the asteroid struck down, ending the Mesozoic and so starting a new period of history of life, the delay of this mass extinction changed some aspects of evolutionary development of many groups, mammals did not became the only dominant clade in this time, many reptiles survivors have also took over, and with the short span of time that has passed to our modern times, the fauna amalgamation is a sort of reminiscence of the Eocene and even the Triassic, but cooler as the planet faced the glacial ages up to the Pleistocene.

In the ocean marine mammals are a thing of course, but they aren’t alone, Choristodere and crocodiles are also common if not predominant in the coasts and freshwater regions by a large amount, choristoderes in fact are coming in a path convergent to sauropterygians now resembling those to a big degree, with varied short body and long necked forms, predatory forms similarly to nothosaurs and very long finned forms that move across the open ocean, they have been very versatile to deal with the subsequent cooling of earth of the last 20 million years, and remain at top even with the new wave of mammals to take over the temperate and cold regions.

Among these, there are the largest coastal predators of the north hemisphere, a fully aquatic species that would look like an imitation of the Mesozoic pliosaurs, along them there are gracile fish eater forms that looks more kind to a plesiosaur, their jaws are narrower and their necks and flippers are longer, but this is no more like the juvenile of this same giant.

The Mocker Retroleviathan is a descendant of smaller choristoderes that ventured into the oceans million years before the mass extinction that already established through the extended later cretaceous thanks to the minor extinction events caused by the ecological transitions of those million years, and after the cataclysm the empty ocean left behind by the large reptiles were early claimed by these reptiles in a short time, becoming megafauna and spreading across the oceans.

The Retroleviathan is the most formidable of these, reaching up to 7 meters and weighting 2 tons, it normally feeds on different large animals including other large choristoderes, some of the piscivorous pelagic crocodilians and the increasingly large para-cetos which are derived multies that adopted fully an aquatic lifestyle resembling an archeocete with a sirenian head but with unique dentitions. They are viviparous, a female can gestate more than 10 offspring which at birth are quite independent of their parents, only being sheltered in the nearby of the territory of the adults until they reach maturity.