Genus: Desmatosuchus

…an extinct genus of aetosaurs that lived during the Late Triassic in Texas. Desmatosuchus possesses a heavily armored body with two long pairs of spikes that jutted out of its shoulders. These spikes are unusual among aetosaurs and were likely evolved to give it extra protection against predators. Despite its fearsome appearance Desmatosuchus was a herbivore and used its pig-like head and shovel-like snout to uproot soft plants.



Images: National Park Service and Petrified Forest

Daily Paleo Art Month #15: Desmatosuchus

Desmatosuchus lived around 230 million years ago in the Late Triassic of Texas, USA. At 5m long (16’4”) it was one of the largest of the aetosaurs, a group of crocodilian-like archosaurs which were very widespread and successful up until the Triassic-Jurassic mass extinction.

Aetosaurs were bulky herbivores with pig-like snouts, and very heavily armored bodies. Desmatosuchus had especially larges spikes over its shoulders, up to 45cm (18in) long, presumably as protection against predators.

Desmatosuchus, one of that mighty lineage of armor-backed pseudosuchians, the aetosaurs (or as Darren Naish once aptly termed them, the armadillodiles). It joins its distant relatives ShuvosaurusEffigia, and Simosuchus in defying the carnivory we may come to expect from croc-line archosaurs. The shovel-like snout and peg-shaped teeth of aetosaurs would seem to pin them as herbivores.

All the same, it has been postulated before that these were instead adaptations for insectivory, and an abstract has been around since 1995 toting around the supposed discovery of a carnivorous aetosaur. Personally I wouldn’t be surprised if they were something more akin to boar-like, omnivorous scavengers of Triassic forests.

Desmatosuchus was among the larger members of the family, spanning about 5 meters (16 feet) in length. It’s known from the Late Triassic of Texas.

The link Crocodile, Desmatosuchus (1920)

Phylum : Chordata
Class : Reptilia
Order : Aetosauria
Family : Stagonolepididae
Subfamily : Desmatosuchinae
Genus : Desmatosuchus
Species : D. spurensis, D. smalli, D. haplocerus

  • Late Triassic (228 - 203,6 Ma)
  • 5 m long and 1 000 kg (size)
  • Texas, United States (map)

Desmatosuchus is one of the better known aetosaurs that were squat quadrupedal archosaurs that fed upon low growing vegetation.‭ ‬This diet is suggested by the presence of peg like teeth that were best suited for stripping off fronds of fern-like vegetation.‭ ‬Not only is Desmatosuchus one of‭ ‬the better known of its group but at up to five meters long it was one of the largest.

The key area that Desmatosuchus is perhaps most famous for is the armour along its back.‭ ‬All aetosaurs had bony‭ ‬armour down the length of their backs to provide some protection from predators that could rear up and attack them from above,‭ ‬but Desmatosuchus took this protection even further with the addition of two forty-five centimetre spikes that projected sideways from above its shoulders.‭ ‬Other albeit smaller spikes also ran down either side of its body.‭

The spikes that ran down the upper flanks of Desmatosuchus certainly would have made attacks from predators more difficult,‭ ‬but how much protection the larger spikes gave remains uncertain.‭ ‬They would have made shoulder area attacks more difficult,‭ ‬but the head was still relatively unprotected,‭ ‬and if they were just for defence it would make sense that similarly sized spikes would run further up and down the body.‭ ‬The enlargement of the shoulder spikes‭ ‬may therefore be more for the purpose of display,‭ ‬not only to allow Desmatosuchus to identify others of its kind from similarly proportioned aetosaurs,‭ ‬but also a sign of maturity like deer antlers.

"Moving on up to the Triassic, and (Doug) Henderson provides us with one of the more memorable restorations of Postosuchus to feature in a popular book. Here, the sinister archosaurian macropredator adopts a nonchalant air as it tosses a young Desmatosuchus to the skies, perhaps with the aim of breaking off a few of those unpalatable spines. Yet another example of Henderson’s superb and original compositions - a brilliant imagination to match his artistic flair. Gush gush gush. I hear his feet really smell*, though, which is important to take into consideration. Just remember that.”

Mark Vincent at Love in the Time of Chasmosaurs