EGU Blogs

Taphonomy

IPC4 Day 1 – Death is the road to awe

Following on from the previous post, the afternoon symposium was all about the applications and implications of vertebrate taphonomy.

Matt Carrano kicked things off with a great talk on how microfossil bonebeds help to guide our understanding of terrestrial palaeoecosystems. Using sites from the well-known but poorly understood Cloverly Formation, he provided a key insight from abundances from terrestrial microsites into the composition of faunas. This was a particularly appealing talk for me as it contained atoposaurids!

Carina Colombi asked what the effect was of atmospheric CO2 on the evolution and preservation of the terrestrial fauna of the famous Ischigualasto Formation. It seems that decreases in atmospheric CO2 may explain decreases in the number of preserved vertebrate fossils in different horizons.

Tao Deng explored the taphonomy of the vertebrate fauna in the Linxia Basin in Gansu, China. Older individuals from particularly abundant rhino fossils seem preferentially preserved, based on ages inferred from tooth eruption

Adriana Mancuso described her research into taphonomic modes in a Triassic-Jurassic loessite (wind-blown deposit) from Patagonia. Different taphonomic regimes suggest aspects of social aggregation in some animals, for example from the accumulation of groups of juvenile specimens.

Alexander Parkinson gave an interesting talk on insect-bone interactions from the “Cradle of Humankind” in South Africa. There were plenty of types of boring trace, with a possible new ichnotaxon. The spatial distribution and mode of preservation of the fossils suggests extremely rapid burial and fossilisation.

Raymond Rogers brought us back to microfossil bonebeds, from the Upper Cretaceous Judith River Formation in the US. He was looking at huge numbers of fragmentary fossils and what their size and shape can tell us about their diagenensis, in particular how the deposits formed and where the fossils were sourced from.

Vijay Sathe discussed the taphonomy of a new large mammalian fauna from the Quaternary of India, and the possibility of their mode of death. It seems some may have fallen into pits, and subsequently scavenged by predators, with the preferential preservation of younger and older animals.

Leif Tapanila finished things off by looking at the effect of impermeable ash layers within geological basins, and whether their distribution affected the preservation potential of fossil layers by changing hydraulic regimes.

End of day 1! The best part for me of this second symposium was the potential that fossil microsites have in greatly increasing our understanding of diversity through time. Hopefully much more on this in the future.

How do the chemical ghosts of dinosaurs help their preservation?

For some years now, Mary Schweitzer and her team have been researching the idea that organic molecules can be preserved for millions of years, specifically within dinosaurs. They have used a plethora of chemical and biotechnological techniques to demonstrate that, within animals like Tyrannosaurus rex, it is possible to find the residue of structures such as blood vessels and even proteins. Naturally, her research has been met with a whole wad of stiff resistance from the scientific community, seemingly for no other reason than “We don’t like the sound of that..”. Scientific rigour ftw!

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A double-whammy of dinosaur awesomeness. Pun totally intended.

This is a post about pachycephalosaurs. It’s not a post about feathered dinosaurs, huge dinosaurs, or any of the ones which you may be more familiar with from popular media. Pachycephalosaurs were the dome-headed little scrappers of the Cretaceous, around 85 to 66 million years ago. Their name means ‘thick-skulled lizard’ (pachy: thick, cephalon: skull, saurus: lizard), and they were a small group within the larger herbivorous group of dinosaurs called ornithischians.

It’s probably fair to say that these dinosaurs are one of the least popular groups; they didn’t have razor sharp teeth and sickle-switchblade claws, they didn’t grow to the size of houses, and they didn’t have rows of armoured shields and spikes along their backs. What they did have, however, is an unusual behaviour that signifies them as unique, and pretty amazing, beasties.

Fig.1 – A pachycephalosaur suffering an ‘ouchie’, or cranial lesion (PLoS)

Fig.1 – A pachycephalosaur suffering an ‘ouchie’, or cranial lesion (PLoS)

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