Paleontologists have found an odd new species of marine lizard with dagger-like tooth that lived close to the tip of the age of dinosaurs. Their findings, revealed in Cretaceous Analysis, present a dramatically totally different ocean ecosystem to what we see in the present day, with quite a few big high predators consuming massive prey, in contrast to trendy ecosystems the place a number of apex predators — akin to nice white sharks, orca and leopard seals — dominate.
Khinjaria acuta was a member of the household Mosasauridae, or mosasaurs. Mosasaurs weren’t dinosaurs, however big marine lizards, kin of in the present day’s Komodo dragons and anacondas, which dominated the oceans 66 million years in the past, in the course of the period of Tyrannosaurus and Triceratops.
Khinjaria had highly effective jaws and lengthy, dagger-like tooth to grab prey, giving it a nightmarish look. It was a part of an awfully numerous fauna of predators that inhabited the Atlantic Ocean off the coast of Morocco, simply earlier than the dinosaurs went extinct.
The examine is predicated on a cranium and elements of the skeleton collected from a phosphate mine southeast of Casablanca. The examine concerned researchers from the College of Bathtub within the UK, the Marrakech Museum of Pure Historical past, the Museum Nationwide d’ Histoire Naturelle (NMNH) in Paris (France), Southern Methodist College in Texas (USA), and the College of the Basque Nation (Bilbao).
“What’s exceptional right here is the sheer range of high predators,” mentioned Dr Nick Longrich of the Division of Life Sciences and the Milner Centre for Evolution on the College of Bathtub, who led the examine. “We’ve got a number of species rising bigger than an awesome white shark, they usually’re high predators, however all of them have totally different tooth, suggesting they’re searching in numerous methods.
“Some mosasaurs had tooth to pierce prey, others to chop, tear, or crush. Now now we have Khinjaria, with a brief face full of big, dagger-shaped tooth. This is likely one of the most numerous marine faunas seen anyplace, at any time in historical past, and it existed simply earlier than the marine reptiles and the dinosaurs went extinct.”
Morocco’s numerous marine reptiles lived simply earlier than an asteroid struck the Yucatan Peninsula in Mexico. Mud and advantageous particles shot into the excessive ambiance blocked out the solar for months, inflicting darkness and cooling, which drove a lot of the planet’s species to extinction.
Dinosaurs had been worn out on land, and a handful of surviving species of mammals, birds, and lizards diversified to take their place. In the meantime, the identical occurred within the oceans.
Mosasaurs, plesiosaurs and big sea turtles disappeared, together with total households of fish. This opened the best way for whales and seals, and fish like swordfish and tuna appeared. Nonetheless, the ecosystem that developed after the affect was totally different.
“There appears to have been an enormous change within the ecosystem construction prior to now 66 million years,” mentioned Longrich. “This unimaginable range of high predators within the Late Cretaceous is uncommon, and we do not see that in trendy marine communities.”
Fashionable marine meals chains have just some massive apex predators, animals like orcas, white sharks, and leopard seals. The Cretaceous had an entire host of high predators.
Dr Longrich mentioned: “It is not simply that we’re eliminating the previous actors and recasting new ones into the identical roles. The story has modified dramatically.
“Fashionable ecosystems have predators like baleen whales and dolphins that eat small prey, and never many issues consuming massive prey. The Cretaceous has an enormous variety of marine reptile species that take massive prey. Whether or not there’s one thing about marine reptiles that prompted the ecosystem to be totally different, or the prey, or maybe the atmosphere, we do not know. However this was an extremely harmful time to be a fish, a sea turtle, or perhaps a marine reptile.”
Professor Nathalie Bardet, from the NMNH, mentioned: “The Phosphates of Morocco deposit in a shallow and heat epicontinental sea, underneath a system of upwellings; these zones are brought on by currents of deep, chilly, nutrient-rich waters rising in direction of the floor, offering meals for giant numbers of sea creatures and, consequently, supporting a variety of predators. That is most likely one of many explanations for this extraordinary paleobiodiversity noticed in Morocco on the finish of the Cretaceous.”
“The phosphates of Morocco immerse us within the Higher Cretaceous seas in the course of the newest geological instances of the dinosaurs’ age. No deposit has offered so many fossils and so many species from this era,” mentioned Professor NE. Jalil of NMNH. “After the’ titan of the seas’, Thalassotitan, the ‘saw-toothed’ mosasaur Xenodens, the ‘star-toothed’ mosasaur, Stelladens and lots of others, now there may be Khinjaria, a brand new mosasaur with dagger-like tooth.
“The elongation of the posterior a part of the cranium which accommodated the jaw musculature suggests a horrible biting power.”
