Estemmenosuchus uralensis

* **Name:***Estemmenosuchus* ‭(‬Crowned crocodile‭)‬.
* **Phonetic:** Ess-teh-men-oh-soo-kuss.
* **Named By:** Chudinov‭ ‬-‭ ‬1960.‭
* **Synonyms:** *Anoplosuchus tenuirostris, Estemmenosuchus uralensis, Zopherosuchus luceus*.
* **Classification:** Chordata,‭ ‬Synapsida,‭ ‬Therapsida,‭ ‬Dinocephalia,‭ ‬Estemmenosuchidae.
* **Species:***E.‭ ‬uralensis,* (type)*‭ ‬E.‭ ‬mirabilis.*
* **Diet:** Herbivore.
* **Size:** *E. uralensis* about 4.5 meters long, *E. mirabilis* about 3 meters long.
* **Known locations:** Russia,‭ ‬Perm region.
* **Time period:** Wordian of the Permian.
* **Fossil representation:** Several specimens of complete and partial remains of individuals,‭ ‬including skin impressions.

Although other herbivorous therapsids like *Styracocephalus* also had head crests,‭ *‬Estemmenosuchus* had by far the most elaborate head ornamentation.‭ ‬These crests varied between the two species,‭ ‬but superficially the head ornamentation resembled short deer antlers.‭ ‬The horns of *Estemmenosuchus* grow upwards from the frontal skull bones and seem to have primarily been display devices.‭
       As with many of the therapsids the exact diet of *Estemmenosuchus* is still a subject of debate amongst palaeontologists.‭ ‬Some have pointed to the sharp canines and incisors and declared *Estemmenosuchus* to be a carnivore.‭ ‬However many of the herbivorous tharapsids still support carnivore like teeth,‭ ‬and the sheer bulk and size of the body suggest that it was shaped to incorporate a large digestive system.‭ ‬As a general rule herbivores have larger bodies to accommodate a longer and more complex digestive system because plant matter takes longer to digest than animal meat.‭ ‬This is why most palaeontologists consider *Estemmenosuchus* to be a herbivore,‭ ‬although some concede that it may have supplemented its plant diet with meat‭ ‬and if this were true,‭ ‬then *Estemmenosuchus* would be an omnivore.

Another piece of evidence to support the herbivore theory is how the legs are orientated.‭ ‬The rear legs are situated directly under the hips supporting the body weight from underneath.‭ ‬By themselves this would suggest that *Estemmenosuchus* spent a lot of time walking as it would provide a more energy efficient form of locomotion.‭ ‬The front legs however sprawl out to the sides similar to how you see them in modern lizards.‭ ‬While this has been suggested to improve manoeuvring so that the head ornamentation is pointed towards a rival *Estemmenosuchus*,‭ ‬or even a potential predator,‭ ‬a more obvious benefit is that these legs would allow *Estemmenosuchus* to lift its forward upper body up and down,‭ ‬kind of like it was doing push ups.‭ ‬This pairing of different limb attachments would suit a herbivore better than a carnivore because it would still allow for more efficient walking when *Estemmenosuchus* searched for suitable food,‭ ‬while also allowing *Estemmenosuchus* to lower its head to the ground for easier low level browsing.

The large size and bulk of *Estemmenosuchus* have also brought the suggestion that *Estemmenosuchus* was gigantothermic.‭ ‬This is where an animal has a low surface area to body mass ratio resulting in the outer tissue layers insulating the inner layers.‭ ‬This increases the base temperature of the animal giving it a metabolism close to a warm blooded creature without the usual adaptations that would suggest it was warm blooded.