How did Plesiosaurs lay eggs?

Scientists say they have found the first evidence that giant sea reptiles – which lived at the same time as dinosaurs – gave birth to live young rather than laying eggs.

How did dinosaurs give birth to their young?

For more than a century, paleontologists have been confident that all dinosaurs reproduced by laying eggs. After all, no dinosaur gave birth to live young (nor do their modern bird descendants), and nesting sites found from Montana to Mongolia indicate that prehistoric dinosaurs laid clutches of sturdy eggs.

Do dinosaurs give birth live young?

As far as we know, all dinosaurs reproduced by laying eggs, as do most other sauropsids (reptiles). It is very difficult to determine what species of dinosaur laid the eggs that have been discovered, because only a few dinosaur embryos have been found inside the fossil eggs.

Did plesiosaurs have live birth?

Think less sea monsters, more doting parents: the long-necked plesiosaurs that roamed the seas during the dinosaur era gave birth to live young. They probably cared for their offspring and may even have lived in large social groups, like modern-day whales.

Where did the plesiosaurus live?

Plesiosaurs had a wide distribution in European seas and around the Pacific Ocean, including Australia, North America, and Asia.

Did brontosaurus lay eggs?

The film’s fictional Brontosaurus baxteri is said to be capable of live birth. Instead of laying clutches of small eggs, gravid Brontosaurus females delivered between one and three large, live offspring at a time.

Did T Rex lay eggs?

No T. rex eggs or nests have ever been found, but fossils of other Tyrannosaur relatives suggest that they laid elongated eggs, roughly 20 or more at a time.

Did dimetrodon lay eggs?

Dimetrodons need to be swimming in water to lay eggs regularly. Dimetrodons on land very rarely lay eggs. One way to determine if the water is deep enough is to feed them about 30 stimberries and see if they poop.

What was the first dinosaur born?

For the past twenty years, Eoraptor has represented the beginning of the Age of Dinosaurs. This controversial little creature–found in the roughly 231-million-year-old rock of Argentina–has often been cited as the earliest known dinosaur.

Did plesiosaurs lay eggs or give birth?

An exciting new paper published this week in the journal Science (Vol. 333, p.870-873) provides the first direct evidence for live birth in plesiosaurs, and may have implications for plesiosaur behaviour (O’Keefe & Chiappe, 2011). Whether plesiosaurs laid eggs or gave birth to live young has been a topic of speculation for nearly 200 years.

Did ancient ‘sea monsters’ give live birth?

Pregnant Fossil Suggests Ancient ‘Sea Monsters’ Birthed Live Young. “This is the first known pregnant plesiosaur. It demonstrates that the plesiosaur gives live birth and did not crawl out on land [to lay eggs]. It puts this 200-year mystery to rest,” said study researcher Frank O’Keefe, of Marshall University in West Virginia.

What are the ancestors of plesiosaurs?

(Paleontologists disagree about the exact lineage, and it’s possible that the plesiosaur body plan evolved convergently more than once.) Some experts think the earliest marine ancestors of the plesiosaurs were the nothosaurs, typified by the early Triassic Nothosaurus .

What makes a plesiosaur unique among marine reptiles?

Plesiosaurs were apparently unique among marine reptiles living during the age of dinosaurs in that they gave birth to single, large young, a trait more commonly associated with marine mammals rather than other reptiles. (Image credit: S. Abramowicz, Dinosaur Institute, NHM)