fossils

Miniature Crocodile Ancestor Uncovered on Scottish Island

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Jackson
Chambers

Writer
The discovery of a 168 million year old jaw fragment on the Isle of Skye in Scotland provides new information on the evolution of “dwarf crocodiles” and other crocodilians.

In the Middle-Jurassic on Scotland’s Isle of Skye, “dwarf crocodiles” lived among dinosaurs. At this point in time, Skye was a tropical island with rivers, lagoons, and lakes. These provided a more than suitable environment for the semiaquatic Theriosuchus. They also supported a huge diversity of life.


At one foot long, Theriosuchus was a small animal. This was likely due to niche specialization, where a single species evolves to carry out a very specific role in an ecosystem. Specializing in such a way can reduce competition with other animals of similar lifestyles. Alternatively, its small size could have been the result of living on an island isolated from other crocodilian populations. This would have caused Theriosuchus to diverge off of the typical crocodilian evolutionary path.


Although the discovered fossil was merely a fragment of a jaw, researcher Mark Young and his team were able to figure out the the animal’s identity. Theriosuchus is considered to be a member of the group Neosuchia, which includes all living crocodilians as well as their closest fossil relatives.

Living crocodiles also belong to a sub-group called Eusuchia, which Theriosuchus was not placed in. This is because of differences in the shape and orientation of their choanae (openings in the nasal cavity that aid in breathing) and differences in the articulation of their vertebrae. Other Theriosuchus fossils have been found scattered throughout Eurasia and Nothern Africa.


Today, the Isle of Skye has an oceanic climate with mild temperatures and weather. It is a popular tourist destination, boasting one of the oldest archaeological sites in Scotland. There are likely many more unique and rare fossils to be found there, peaking the interest of many paleontologists.


References:
http://www.forbes.com/sites/shaenamontanari/2015/09/11/ancient-dwarf-crocodile-relative-discovered-on-scottish-isle/#747269f5575e
http://onlinelibrary.wiley.com/doi/10.1111/zoj.12315/full
http://onlinelibrary.wiley.com/doi/10.1111/zoj.12400/full

Image Credit: Joschua Knüppe

D0ffa1e0b9aae1b8eb82bb07c0e01c81

Jackson
Chambers

Writer


http://sulc.us/i35xh
http://www.eartharchives.org/articles/miniature-crocodile-ancestor-uncovered-on-scottish-island/