Living Archosaurs

In our research the anatomical data from the living relatives of Triassic crocodiles and dinosaurs will help us estimate muscle function in these extinct animals.

The living relatives of Triassic crocodiles include Nile crocodiles (Crocodylus niloticus) and the living relatives of dinosaurs are birds including the Tinamous  (Eudromia elegans);  both of which we are looking at in our study.

Crocodylus niloticus (Nile Crocodile)

Geographic area: Eastern Africa from Egypt in the North to South Africa in the south20170322_124153 cropped 2, even extending east to Madagascar. A debate exists about the crocodiles in West Africa and whether they are C. niloticus or belong to a separate species (C. suchus).

Details: The Nile Crocodile is the second largest of the living species of crocodiles, with the largest known individual measuring 6.45m and weighing 1090kg. Using an ambush hunting style from the water and a bite force of 22,000 Newtons, prey is captured and drowned before being dismantled and swallowed in chunks. These attacks are famously featured in many wildlife documentaries, particularly on wildebeest and zebra crossing rivers during the great migrations across the Masai Mara. However, as in all other Crocodylia, because crocodiles hatch at small sizes and grow slowly, they occupy a spectrum of ecological niches throughout their lifetime (e.g. eating small fish and arthropods early in life) and have extensive mortality at young, vulnerable life stages.

Why we are studying them? Nile crocodiles are mostly aquatic, swimming with their legs tucked against their body. On land, the crocodiles tend to walk in sprawling quadrupedal postures, either sliding on their bellies or more upright “high walks”. However, small individuals are capable of a far wider range of movements including galloping (bounding) and jumping, which are more similar to what we predict the fossil crocodile (crocodylomorph) species; and maybe other archosaurs; were capable of.


Eudromia elegans  (Elegant crested tinamou)

Geographic area: Southern Chile and Argentina

TinamousKnown details:  The elegant crested tinamou is a small bird commonly found across the southern end of South America, although other tinamou species are found across Central and South America. About the size of a common wood pigeon, the tinamous are the only living palaeognaths capable of flight. However, they spend a large proportion of their time on the ground whilst foraging for fruit, nuts, seeds and insects.

Why we are studying them? Tinamous most closely match the anatomy and behaviour of the most recent common ancestor of modern birds (although no modern bird is expected to be identical to that ancestor). Thus they are an ideal living bird species to be working on for comparison to early dinosaurs.