Paleontology Headline: Caiman Bites Sloth

Predation of the giant Miocene caiman Purussaurus on a mylodontid ground sloth 2020. Figure 2:Life reconstruction of the putative attack of a young to sub-adult Purussaurus on the ground sloth Pseudoprepotherium in a swamp of proto-Amazonia. Art: Jorge A. González.

It only took one 13-million-year-old bone for two paleontologists to reconstruct the dramatic encounter pictured above. That bone is a tibia, or lower leg bone, from an extinct ground sloth (not a giant ground sloth, just a 170 pound medium-sized one). The tibia has 46 tooth marks on it, made by the extinct caiman (a close relative of alligators) Purussaurus.

Read the paper by Pujos and Salas-Gismondi to see how, through a detailed taphonomic analysis of a single bone, they were able to infer not only what animal did the biting, but also how old it was. Unresolved: whether the caiman got the whole sloth or just the leg.

Detail of Figure 1: Left tibia of Pseudoprepotherium sp. (MUSM 1587) and mapping of the bite marks, from Pujos and Salas-Gismondi 2020.


Predation of the giant Miocene caiman Purussaurus on a mylodontid ground sloth in the wetlands of proto-Amazonia

Pujos F, Salas-Gismondi R. 2020 Predation of the giant Miocene caiman Purussaurus on a mylodontid ground sloth in the wetlands of proto-Amazonia. Biology Letters 16: 20200239.

Featured image: Detail of Figure 2 from Pujos and Salas-Gismondi. Artwork by Jorge A. González.

Deep Water Taphonomy

A new PLOS One article documents the carcasses of a whale shark and three rays found at a depths over 1,200 meter, providing a rare opportunity to learn about deep water taphonomic processes and the biotic communities that live off of these food falls.

No collections or measurements could be made, but they have photos and videos.

Higgs ND, Gates AR, Jones DOB (2014) Fish Food in the Deep Sea: Revisiting the Role of Large Food-Falls. PLoS ONE 9(5): e96016. doi:10.1371/journal.pone.0096016

See a summary of the article at Live Science.