Despite that there are about 600 Crinoid species, they’ve mostly gone extinct. Being a marine animal, their fossils are mostly found in thick limestone beds dating to the mid-to-late-Paleozoic. [http://bit.ly/2j9r9ml]
Teraterpeton, an unusual archosauromorph from the Late Triassic of Nova Scotia, Canada (~235-221 mya). Probably around 1m long (3′3″), it was a member of the trilophosaurs, a group of lizard-like archosauromorphs with toothless beaks at the front of their jaws and chisel-like cheek teeth at the back.
It had a very long, thin, rather bird-like snout, with a huge nasal opening, and a euryapsid-type skull with the lower temporal fenestra closed off – a condition seen in some marine reptiles like ichthyosaurs and plesiosaurs, but unique among all its close relatives.
Its forelimbs also had deep narrow blade-like claws, and the rest of its body is only known from fragmentary remains. It was clearly adapted for some sort of highly specialized niche in its ecosystem, but we just don’t yet know what that niche actually was.
Maybe one day we’ll find more complete fossils of this odd animal and get some answers… or even more surprises.
“Primitive Condition”, a watercolour sketchbook drawing of a Sandhill crane that has reverted to its theropod dinosaur ancestry. Sketched this initially from a prepared specimen in the Sacramento state vertebrate collection and altered the features. I liked how the crane had its head bent. Though it’s simply so that the specimen is not damaged when handled and placed in storage, there is something emotional to it, I think… Cranes are significant, and bear a lot of symbolism. They’re an ancient group of birds.
This living fossil is sometimes called shield shrimp. Triops australiensis is native to Australia, but other species of shield shrimps can be found nearly all around the world. It inhabits temporary pools of water and due to this after hatching from egg it develops rapidly to adulthood.
The first four-legged fossil snake ever found is forcing scientists to rethink how snakes evolved from lizards.
Although it has four legs, Tetrapodophis amplectus has other features that clearly mark it as a snake, says Nick Longrich, a palaeontologist at the University of Bath, UK, and one of the authors of a paper describing the animal in Science1.
The creature’s limbs were probably not used for locomotion, the researchers say, but rather for grasping prey, or perhaps for holding on to mating partners. Such speculation inspired the snake’s name, which loosely translates as ‘four-legged hugging snake’.
Tetrapodophis was originally found in the fossil-rich Crato Formation in northeastern Brazil several decades ago. But its legs can be difficult to see at first glance, and it languished in a private collection after its discovery, assumed to be unremarkable.
“I was confident it might be a snake,” says David Martill, a palaeobiologist at the University of Portsmouth, UK, who came across the find in 2012. “It was only after getting the specimen under the microscope and looking at it in detail that my confidence grew. We had gone to see Archaeopteryx, the missing link between birds and dinosaurs, and discovered Tetrapodophis, the missing link between snakes and lizards.”