Long before the age of the Pharaohs and the monumental construction that defined the ancient Egyptian world, the famed Gift of the Nile was once a sea filled with hungry monsters.
Today, evidence of these ancient aquatic beasts can still be found in Egypt’s sands, as revealed in a new study appearing in Cretaceous Research, which sheds new light on the diversity of ancient shark communities that swam modern-day Egypt’s ancient oceans in the Late Cretaceous.
Adding to the known species of sharks from this era, the new research has revealed five additional species of ancient marine predators that once thrived there, fossils of which were among those unearthed in a fossil tomb very unlike those excavated by Egyptologists over the last two centuries.
During the Cretaceous period, Earth saw much higher temperatures, which also meant less ice accumulation around the poles. That abundance of liquid water caused by the greenhouse effect during this period in Earth’s history, therefore, led to much higher ocean levels than those seen today.
In Egypt’s Western Desert today, a vast tropical sea once existed 150 million years ago along what is recognized as the Abu-Tartur Plateau, which is home to the fossil-rich Duwi Formation. There, organic sediments collected over vast periods, which helped to create the phosphorite deposits that were conducive to fossil formation, thereby preserving a record of the ancient species that once thrived there.
Past studies had already documented several ancient shark species from the region’s Cretaceous oceans, prompting the additional research detailed in the new study. According to the team’s findings, more than a dozen new fossil shark teeth were recovered from the area around the Abu-Tartur mine, displaying a remarkable diversity.
Based on their individual characteristics, paleontologists have identified the new specimens based on existing records kept in museum collections and other record sources.
Of fourteen teeth the researchers uncovered from phosphorite beds during their field work, at least five extinct varieties of lamniform sharks—a variety known as mackerel sharks—were uncovered, which brings the number known to have once inhabited the region up to seven.
Of the five newly identified varieties, two species—Squalicorax bassanii and Serratolamna serrata—were previously unknown to Egypt, while one other variety, Scapanorhynchus raphiodon, appears to have been an ancient ancestor of the odd-looking goblin shark. Modern varieties of this species are known to thrive around continental shelves and seamounts throughout the Atlantic, Pacific, and Indian oceans, although the ancient relative identified in the new research had never previously been found anywhere on the African continent.
If confirmed, the recent Egyptian discovery could also indicate the earliest known presence of this species in Earth’s ancient oceans.
The new findings reveal new insights into the nature of Earth’s ancient seas, revealing that the prevalent nutrients in the tropical waters of the Cretaceous helped to foment a thriving ancient shark community.
“Collectively, this assemblage highlights a nutrient-enriched, high-productivity marine ecosystem along a phosphogenic shelf margin, most likely developed during a transgressive systems tract in the Late Cretaceous,” the study authors say.
The recent paper, “Egyptian shark graveyard: New Late Cretaceous Lamniform shark Assemblage from Duwi Formation of Abu-Tartur Area, Southwestern desert, Egypt,” appeared in Cretaceous Research.
Micah Hanks is the Editor-in-Chief and Co-Founder of The Debrief. A longtime reporter on science, defense, and technology with a focus on space and astronomy, he can be reached at micah@thedebrief.org. Follow him on X @MicahHanks, and at micahhanks.com.
Marine biologists have identified a new species of the shark genus Hemiscyllium in the waters of eastern Papua New Guinea, expanding a remarkable group of reef-dwelling sharks known for using their four fins to ‘walk’ across the seafloor.
The post New Species of Walking Shark Discovered off Papua New Guinea appeared first on Sci.News: Breaking Science News.
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