Shringasaurus

Credit: PrehistorybyLiam on DeviantArt.

*Shringasaurus* is an extinct genus of archosauromorph reptile that lived in India during the Middle Triassic.

## Description

*Shringasaurus* sports a large body size along with two curled horns atop its head. The function of the horns likely were a product of sexual selection. The male individuals may have locked horns or head-butted one another to win a mate. *Shringasaurus* is quadrupedal, walking in four strong limbs. The skull was boxy, sporting two long horns that curved forward in front of the eyes. *Shringasaurus* had deep shoulders and ribs, which supported a considerably thick neck and a barrel-shaped body. *Shringasaurus* also had a long tail, which may have dragged on the ground. *Shringasaurus*' neural spines are at their most elongated at the neck and between the shoulders.

Not much material of the skull is known. The skull is boxy, has a rounded tip, has a deep snout and has bony nostrils which fuse into a singular confluent opening at the front of the skull. The horns themselves sit at the front of the eyes and stretch forward almost the entire skulls length. Individuals have different horn sizes and orientation. Juveniles bear short and gracile horns, countering the adults. This means that *Shringasaurus* developed their horns at sexual maturity. Interestingly, one specimen lacks horns all together. Another has small, yet well-developed horns. Perhaps, females lacked horns and males grew large ones, making them sexually dimorphic. Horns have a rough and grooved texture, meaning they were sheathed by a keratin structure. Like ceratopsian horns, they may have been longer than the bony skeleton suggests. The skull bones beneath the horns are usually dense, and larger animals have fused nasal, prefrontal, frontal and postfrontals. Shringasaurus has leaf-shaped teeth, with large denticles on each side. Because the mandible is largely unknown, the total tooth count is also unknown. Only known from the vomer, Shringasaurus appears to have many palatal teeth. The presence of these teeth are strange, because they are more leaf-shaped than others, while other herbivores have a simpler dome shape.

*Shringasaurus*' vertebral column is very well known. The entire cervical series, several dorsal, both sacrals and several caudal vertebrae are represented. The first down to the middle cervical vertebrae are elongated, as in all azendohsaurids, supporting a thick and characteristically short neck. The neural spines give *Shringasaurus* a much wider neck than common in Azendohsauridae. This height carries on through the back, which are not as long as the neural spines but twice as long as the centra. Through the 2nd and the 5th cervical vertebrae, *Shringasaurus* bears prominent epipophyses, which attached the neck muscles, meaning that *Shringasaurus* had strong neck muscles. As well, the first 12 dorsal vertebrae are covered in several prominent laminae, which bounds deep fossae. This feature is very similar to the vertebrae of sauropods. Two sacrals with well-developed ribs articulate the ilia.

The forelimb and the shoulder bear a tall scapula that is concave, with an expanded tip, an interclavicle with and elongated paddle-like function on its back and a short, forward-facing function at its front. Both the scapula and the coracoid articulate, to create a glenoid that is positioned outwards and to its rear. This means that *Shringasaurus* held an upright position more often than it did a sprawling position. The humerus is similar. Two broad ends with a slimmer shaft, and a developed deltapectoral crest, which measures about half of the whole bones length. Additionally, this also supports the theory that Shringasaurus had powerful limbs. The ulna distinguishes from the olecranon process below the elbow. Both the hips and hindlimbs are similar to *Azendohsaurus*. The illiums process is semi-circular in shape in front, and the rear process is more elongate and skinny. The acetabulum is solid, unlike the perforated structure in dinosaurs. The femur is robust, and slightly S-curving, held in a sprawling gait. The tibia is also robust, and the fibula is half the length of the lower leg. The foot seems to be shared among archosauromorphs, as long as *Shringasaurus*' closest relatives.

## Paleobiology

### Horns

The most prominent feature of *Shringasaurus* is its curved horns. The initial theory by the authors was that the horns were a product of sexual selection, rather than defense or species recognition. Larger adults grew larger robust horns, while younger, or smaller, individuals grew small, more gracile horns. Females likely lacked this feature, altogether. This would be very much like bovids, and unlike ceratopsian dinosaurs. Compared to other animals, the horns were curved and relatively short. Opposed to ramming, fencing or headbutting, *Shringasaurus* likely wrestled with their horns. Males may have competed by locking horns, as hypothesized in Triceratops and seen in the modern reeduck antelope.

### Pathologies

One specimen of *Shringasaurus* shows a documented case of a pair of malformed vertebrae in its neck. Two cervicals are partially conjoined, theorized as a result of a birth defect, a form of arthritis known as spondyloarthropathy, or even a fungal/bacterial infection in the disc. This pathology was seen in a large adult, which means that the malformity was not fatal, nor took a toll on the animals life. One vertebrae bore a healed fracture, although the cause of the injury is not known.

## Paleoecology

*Shringasaurus* coexisted with the lungfish *Ceratodus* sp., temnospondyls *Paracyclotosaurus*, *Cherninia*, Trematosauridae indet. and Brachyopidae indet.. Other terrestrial animals include an undescribed rhynchosaur, two dicynodonts and material loosely assigned to *Kannemeyeria* and *Stahleckeria*. The paleoenvironment is thought to have been dry and semi-arid, with slow anabranching rivers that burst their banks periodically. Rain was seasonal and the dry season dried up many bodies of water. Because *Shringasaurus* may have played a similar role as sauropodomorphs, as high-browsing herbivores.

## References

https://en.wikipedia.org/wiki/Shringasaurus