ARIZONASAURUS

Arizonasaurus babbitti

Etymology: Babbitt's Arizona lizard

Nickname: "Arizona"

Classification: Pseudosuchia, Ctenosauriscidae

Diet: Carnivore

Size: 3.5 meters long

Provenance: Moenkopi Formation, Arizona, USA - Middle Triassic, Anisian stage, 243 million years ago

Movie appearances: Jurassic World: Dominion (2022)

Arizonasaurus babbitti was a ctenosauriscid pseudosuchian, part of a large group of archosaurian reptiles that was pretty dominant during the middle-late Triassic period. This reptile had a strong toothed jaw for hunting down other animals, for it was a carnivore, and possesses a few distinguishing characteristics, like a deep fossa hidden from view on the posteroventral edge of the upward-pointing process of the maxilla, and a tongue-groove attachment between the pubis and the ilium.

Arizonasaurus was an animal already long ambitioned to be resurrected, with a statue of it being held in Benjamin Lockwood's museum in his manor, though the species was only successfully resurrected by Biosyn.

Resurrected Arizonasaurus resided in the Biosyn Sanctuary, located in Italy, specifically living in and around the abandoned amber mines. In 2022, Maisie Lockwood, Alan Grant and Ellie Sattler were stranded there after the Hyperloop shut down, with an Arizonasaurus first stalking them from the water. Later the group was confronted by a multiple number of Arizonasaurus. While trying to escape through a locked exit door, the trio tried to block the pseudosuchians with a mine cart, but the reptiles climbed in to try and catch them, but eventually the humans escaped by calling out for help to open the door. The Locustrix forest fire that happened soon after doesn't seem to have affected the Arizonasaurus. The Biosyn Sanctuary was later turned into an international wildlife reserve, with the Arizonasaurus freely living in the amber mines and in the adjacent wilderness.

FILM vs. REALITY

DISCLAIMER: Arizonasaurus does not show up in the Jurassic Park films, and it is instead, here, meant to be a plausible substitute to the films' Dimetrodon. The film Dimetrodon has a few differences from its original counterpart. The real life Dimetrodon had a very characteristic skull shape that differs from the one in the film that resembles the one from this franchise's iteration of Tyrannosaurus rex. Although Dimetrodon is realistically reconstructed in the films with a splayed limb posture, a scaly skin and a large thin dorsal sail, it still has a few details that are questionable. We know that the sail didn't have skin covering the tips of it, with a notable portion of the tips of the vertebrae possibly being covered by a hardened texture, with the skin reaching just below it. Dimetrodon is also shown in the films with series of lumps that may resemble osteoderms, which are not believed to have been present in the species, though our knowledge on the integument of basal synapsids (the group that Dimetrodon belonged to) is incomplete, so its not a totally unreasonable speculation. The films show Dimetrodon being an adept swimmer, and although this animal did not show clear signs of aquatic adaptations in its anatomy, we know that it actively procured aquatic prey, so it being good at swimming is very plausible.

However, the Jurassic Park franchise tends to give spotlight to Mesozoic animals, so the inclusion of Dimetrodon, which lived in the Paleozoic era, breaks this trend in the franchise. Because of that, Arizonasaurus is brought in as a replacement, for it is an animal from the Mesozoic era that resembled Dimetrodon in appearance. It, however, belonged to a completely different branch of animals, for it was a reptile, distantly related to crocodilians. It differs vastly from Dimetrodon in the possession of erect limbs (typical of archosaurs) and a diapsid skull with more openings to make it light weight but still sturdy enough to be effective at catching prey. Its sail was fully covered in skin, however. Although there is no evidence that Arizonasaurus was capable of aquatic habits, it did inhabit a coastal setting filled with meandering rivers, so it could have definetly benefited from traversing waterways to keep up with promising prey.