Outside/In on the Darién Gap

Here’s a podcast about the Darién Gap that’s NOT about somebody trying to drive through it (but also, tell me more about that drive north of Montreal) .

There are places on the map where roads end.

The Darién Gap, or el Tapon del Darién, is one of them. It’s a stretch of rainforest in southern Panama, right on the edge of Central and South America. From a globetrotter’s perspective, the Darién Gap might seem to exist mostly as an obstacle to tourists dreaming of a truly epic road trip from Alaska to Tierra Del Fuego.

But, while a road is one way for movement, it’s not the only way to get somewhere. What happens, or does not happen, in a place without roads?

Outside/In produced by Sam Evans-Brown with Justine Paradis and Taylor Quimby.

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. http://dx.doi.org/10.1098/rsbl.2020.0239

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