Palaeontologists have discovered the world's first swimming dinosaur in Morocco

[unhappycamper]

http://ibnlive.in.com/news/palaeontologists-have-discovered-the-worlds-first-swimming-dinosaur-in-morocco/498513-79.html



In a surprise find, palaeontologists have discovered the world's first known swimming dinosaur.

Palaeontologists have discovered the world's first swimming dinosaur in Morocco
IANS
Sep 13, 2014 at 09:57am IST

New York: In a surprise find, palaeontologists have discovered the world's first known swimming dinosaur - a 15-metre-long behemoth with a crocodile-like face.

The creature called Spinosaurus aegyptiacus had feet well suited to paddling and a sail-like structure rising from its spine.

It also had unusually dense bones, possibly to help weigh it down as it hunted its underwater prey.

"It is the first dinosaur that shows these really incredible adaptations. There is no doubt in my mind that Spinosaurus would have done most of its hunting in the water," claimed team leader Nizar Ibrahim from University of Chicago in Illinois.

[Shrike47]

1. This is confusing. What about pleisiosaurs? I read they were reptiles. Weren't dinosaurs?

I always thought of dinosaurs as big lizards. Does this mean they weren't?

[Feral Child]

2. I'm not an expert.

But no, they weren't the same. For one thing, many dinosaurs are now considered to be warm-blooded.

[muriel_volestrangler]

3. They were reptiles, but not dinosaurs

They were more closely related to true lizards than dinosaurs were:

Lepidosauromorpha is a group of reptiles comprising all diapsids closer to lizards than to archosaurs (including crocodiles and birds). The only living sub-group is the Lepidosauria: extant lizards, snakes, and tuataras. The extinct lepidosauropmorphans are thought to include the plesiosaurs.

Lepidosauromorpha are distinguishable from Archosauromorphs (archosaurs) by their primitive sprawling gait, which allows for the same sinusoidal trunk and tail movement seen in fish, the sliding "joint" between the coracoids and the sternum (for a longer stride), and their pleurodont dentition. In contrast, Archosauromorphs possess a parasagittal gait, a reduction in their dermal girdle, a reduction and/or loss of the sternum, and a more thecodont dentition.

http://en.wikipedia.org/wiki/Lepidosauromorpha

(dinosaurs were archosaurs)

Both the above groups, together with the ichthyosaurs (more swimming reptiles, that evolved to the point where they look superficially like dolphins), are diapsids. It's more accurate to say dinosaurs were big birds, or that they were a sister group of the crocodiles.

So look on this as a monster penguin ...