Swimming with Dinosaurs

Dinosaurs left plenty of bones, but some also created another type of fossil: preserved track marks. A handful of these tracks were made from swimming dinosaurs, and a new paper in the Chinese Science BulletinA new Early Cretaceous dinosaur track assemblage and the first definite non-avian theropod swim trackway from China (open access) – reports on the discovery of one such find.

Timothy L. Clarey’s new article on these tracks is called Dinosaurs Swimming out of Necessity, but the “necessity” conclusion is entirely his own. His article is quite similar to one from Brian Thomas published in January which we looked at in Stampede? For instance both Thomas and Clarey chose to claim in their opening paragraphs that, in the present day, it is very difficult to form footprints that will eventually be preserved as fossils – here’s Clarey’s opener:

What’s so fascinating about dinosaur tracks? Maybe it’s because their many mysteries beg for solutions. For instance, because tracks in mud are so short-lived today, how did dinosaur tracks ever preserve in the first place? Newly described prints bolster biblical creation’s explanation of dinosaur footprints.

It may be true that it’s hard to preserve footprints in mud, but it’s not so improbable once you consider the shear number of footprints that would have been made over the more than 180 million years of the Mesozoic Era. Clarey never does explain, meanwhile, how “biblical creation” suddenly makes preservation so much easier – not even a “footprints need to be preserved rapidly” claim (which is false, by the way). Continue reading

Stampede?

Dinosaur tracks at Lark Quarry The several-thousand prints at the Lark Quarry dinosaur track-ways, in Queensland, Australia, have long been interpreted as being the result of the only known dinosaur stampede. They were caused, it was believed, by a large hungry theropod spooking and scattering a group of smaller dinosaurs. A new paper – Re-evaluation of the Lark Quarry dinosaur tracksite (late Albian–Cenomanian Winton Formation, central-western Queensland, Australia): no longer a stampede? (pdf, SI) – argues that the site does not represent a stampede at all, but dinosaurs swimming with the current as part of a migration. Somehow, Brian Thomas gets from this research the title “New Dinosaur Tracks Study Suggest Cataclysm.” Continue reading