A Theory Discredited: Sauropod Vivipary

 During the late 80s/early 90s, paleonlologist Robert Bakker came up with revolutionary theories that sometimes set the established scientific community on edge.

   One of these was sauropod vivipary, Bakker's revisionist theory that the offspring of large saurpopods such as the above apatosaurus, did not lay eggs, but gave birth to live well, developed young, nurtured by a huge, placenta-like membrane. His theory was a sound one, based on the fact that the birth canal seemed too large for eggs to pass, and there is a limit to how large an egg can get. Saurpods were huge animals, and most likely lived in herds, so either abandoning their egg clutches, or having communal rookeries, seemed far less efficient than giving live birth. 

  As a young child, I recall that picture books often showed sauropods up to their armpits in swamps. Somehow, that just never seemed right to me that animals obviously built for a land-dwelling existence would have trouble supporting their own weight on land. It turned out that I was right. As Bakker helpful explained in his Dinosaur Heresies, and on a memorable TV special called The Dinosaurs, sauropods were herd animals that even favored upland environments. 

It was also true that the whole idea of sauropods laying eggs like a modern chicken didn't seem right either. It seemed almost ludicrous, the paintings of forty-ton brachiosaurs nurturing clutches of eggs. Bakker's theory kind of came to the rescue--it made so much more sense! I even objected to calling young sauropods "hatchlings" in popular media, claiming Bakker got it right.

 

And yet it was proven totally false. Sauropod eggs have revealed intact fetuses, so whatever the details of their reproductive cycle, we now know that sauropods laid rather small eggs. Tradition had it right all along. 

We sometimes forget that dinosaur were alien in relation to the animals familiar to us today, and assume that beasts like sauropods lived similar to elephants today, herding and protecting their young from predators, as evidenced by the main hall display of a mother barosaurus, rearing up in defense of her calf against a predacious allosaurus. Unlike elephants, their nearest analogues in the world of mammals, sauropods had very small brains, and were incapable of elephant like social behavior. They likely did abandon their eggs, and just how sauropod hatchings survived to full gigantic adulthood is up for grabs.

In Peter Jackson's King Kong, however according to the book The World of Kong: a Natural History of Skull Island, the island's extant brontosaurs had developed vivipary during the past 65 million years, and gave birth to live young, just like Bakker's now-falsified theory.