Following the discovery of a 94-million-year-old mosasaur in the gray shale badlands of the National Park Service’s Glen Canyon National Recreation Area in southern Utah, Dr. Barry Albright, a faculty member at the University of North Florida, is a member of a research team that is led by the Bureau of Land Management (BLM). This discovery has resulted in the discovery of brand-new evolutionary information. While dinosaurs ruled the land, Mosasaurs were fully marine-adapted reptiles that swam in the seas. Cretaceous Research has published the groundbreaking discovery.
The journey began nearly 11 years ago when Scott Richardson, a trained volunteer who was working under Dr. Albright, looked for the fossilized remains of creatures that once swam in a vast sea that covered most of North America in the middle of the Late Cretaceous Period, which lasted from 84 to 95 million years ago. On a large shale slope, Richardson discovered numerous small skull fragments and vertebrae of an early mosasaur in March 2012.
“Mosasaurs were still very small, primitive, and in the early evolutionary stages of becoming fully marine-adapted when the Tropic Shale was being deposited, approximately 94 million years ago. “Their fossils are extremely rare and difficult to find due to these factors,” stated Dr. Albright.
“Around 94 million years ago, when the Tropic Shale was being deposited, mosasaurs were still very small, primitive, and in the early evolutionary stages of becoming fully marine adapted. As a result of these factors, their fossils are exceptionally rare and difficult to locate.”
Dr. Barry Albright is part of a research team led by the Bureau of Land Management (BLM)
A joint group from the BLM and Public Park Administration recovered almost half of the example throughout the following two field seasons, enough to determine its precise personality. A team of BLM employees and volunteers worked on the research under Dr. Alan Titus, the paleontologist for the Paria River District. Steve Dahl, a volunteer who was later honored with the species name Sarabosaurus dahli, or “Dahl’s reptile of the mirage,” was a member of the team. The animal’s long-since-disappeared ancient seaway and the mirages that accompany the region’s extreme summer heat are both references in the name.
According to Dr. Titus, “mosasaurs are extremely rare in rocks older than about 90 million years.” However, “mosasaurs from younger rocks are relatively abundant. “It is truly a significant discovery to find one that preserves so much informative data, especially one of this age.”
Although the earliest mosasaurs were only about 3 feet long, they eventually developed into enormous marine predators that resembled lizards and ruled the oceans during the dinosaur era. Although their aquatic cousins evolved streamlined bodies, paddle-like fins, and tails that propelled them through the water, their land-dwelling ancestors were similar to the modern Komodo Dragon. Sarabosaurus had a novel method of delivering blood to its brain, whereas the earlier forms were more lizard-like in appearance and retained relatively primitive tails and limbs.
Dr. Michael J. Polcyn of the University of Utrecht, Netherlands, and Southern Methodist University, Dallas, stated, “Sarabosaurus sheds light on long-standing questions regarding the relationship of some early branching mosasaurid species, as well as provides new insights into the evolution and antiquity of a novel cranial blood supply seen in a particular group of mosasaurs.”
More information: Michael J. Polcyn et al, A new lower Turonian mosasaurid from the Western Interior Seaway and the antiquity of the unique basicranial circulation pattern in Plioplatecarpinae, Cretaceous Research (2023). DOI: 10.1016/j.cretres.2023.105621
