Just how big was that animal? Part 2: Hainosaurus

Again with the organisms whose sizes were formerly overestimated -- early estimates put Hainosaurus as high as 17 meters long. It's now been downscaled to 12.2 meters.

However, as the picture shows (12-meter Hainosaurus compared to 1.75-meter human) that's still very big.


Reference: Lindgren, Johan. The first record of Hainosaurus (Reptilia: Mosasauridae) from Sweden. Journal of Paleontology 2005 79: 1157-1165

Just how big was that animal? Part 1: Deinosuchus

Generally, the first thing everyone wants to know about a new dinosaur (or giant pterosaur, crocodilian, whatever) is how big it is. Sometimes the initial estimates are too big, occasionally unrealistically so - I'm looking at you, 18-meter-wingspan Quetzalcoatlus!

Then the estimates have to be downsized. Often, when I'm reading about an animal, I'm thinking "Darn! It wasn't that big after all." It's kind of disillusioning. And I'm sure others feel that way too.

But! They're still FRICKIN' HUGE. And this series of blog posts will show that.

Today: Deinosuchus. Formerly estimated at around 15 meters, from a skull reconstructed to be 1.8 m long; now estimated at around 10 meters from a skull more confidently 1.31 m long. (This is not the species' maximum size, but larger specimens are very fragmentary, so size can't be well determined.)

This is an American alligator Alligator mississippiensis (source: USFWS), scaled to the size of a Deinosuchus with 1.31 meter skull length. Human silhouette is 1.75 meters.


...pretty impressive. And they got bigger, too.

(For that matter, what are the chances that the largest individuals were among the relatively few that got fossilized, then discovered?)

Marine crocodiles

Among the variety of dinosaurs, one other prehistoric archosaur group often escapes comment: the marine crocodiles.

Here is Dakosaurus maximus in yellow at 5 meters, compared to a modern sea otter in brown at 1.2 meters and two better-known marine reptiles: Mosasaurus in black at 12 meters, and Liopleurodon in green at 9 meters.



Here is a picture of Dakosaurus alone.