All articles tagged with #cretaceous period
A study in Current Biology indicates that certain Cretaceous mosasaurs, such as Tylosaurus, utilized a 'slam start' technique to accelerate to 15 mph for ambushes, while others like Plotosaurus favored sustained swimming speeds.
A remarkably complete fossil from Mongolia’s Gobi Desert, named Tamirkhan balcarceli, has been published in Nature, revealing that zhelestids were not early placental mammals but a distinct group of insectivores. This discovery overturns decades of assumptions based on isolated teeth and highlights the limitations of reconstructing anatomy from partial remains.
A nearly complete fossil of the Cretaceous mammal Tamirkhan balcarceli, found in Mongolia’s Gobi Desert, overturns a four-decade scientific consensus. Previously, isolated teeth suggested zhelestids were early relatives of modern placental mammals. The new specimen reveals they were actually zalambdalestoids, a distinct lineage of insectivores. This finding highlights the limitations of reconstructing anatomy from teeth alone and confirms that zhelestids evolved plant-eating traits through convergence, not shared ancestry with placentals.
A team led by Cairo University’s Dr. Tarek Yassin identified 14 fossilized shark teeth in Egypt’s Western Desert, confirming the area was once a shallow tropical sea. Published in Cretaceous Research, the findings reveal five distinct species, including an ancient relative of the goblin shark, preserved in phosphate-rich rocks from 70 to 80 million years ago.
Archaeologists digging in Egypt’s southwestern desert uncovered a Late Cretaceous shark graveyard within phosphate beds of the Duwi Formation, preserving a former tropical marine ecosystem and 14 fossilized teeth. The find includes five extinct lamniform sharks—Cretalamna cf. C. maroccana, Scapanorhynchus cf. S. raphiodon, Serratolamna cf. S. serrata, Squalicorax bassanii, and Squalicorax pristodontus—offering new insight into Africa’s ancient paleobiodiversity and past sea levels that were significantly higher than today.
A new peer-reviewed study of 17 Tyrannosaurus rex fossils used growth rings revealed by polarized light to map year-by-year growth, showing T. rex took 35–40 years to reach full size and grew for four decades to about 8 tons, with an estimated lifespan of 45–50 years. This large dataset yields a revised growth curve and suggests a lengthy juvenile phase may have helped juveniles occupy varied ecological roles before the species became a dominant late-Cretaceous apex predator.
Scientists discovered a 70-million-year-old dinosaur egg in China that contained calcite crystals, transforming it into a natural geode and leading to the identification of a new species, Shixingoolithus qianshanensis, providing new insights into the microstructure, fossilization processes, and environmental conditions of the Late Cretaceous in the region.
Scientists discovered over 16,000 dinosaur footprints at a large fossil site in Bolivia, many of which suggest dinosaurs moved along the shoreline of an ancient lake, with some footprints indicating swimming behavior, providing valuable insights into dinosaur movement and environment during the late Cretaceous period.
Scientists discovered 10 new fossilized spider species from the Mesozoic era in South Korea, including one with preserved glowing eyes that reflect light, indicating they may have been nocturnal hunters. This rare find, published in the Journal of Systematic Palaeontology, provides new insights into ancient spider diversity and their ecological niches, especially with the first identification of a tapetum in fossilized spider eyes.
Scientists studying the Paja Formation in Colombia have uncovered evidence that ancient oceans were dominated by enormous marine reptiles, some over 10 meters long, filling a previously unseen seventh level at the top of the food chain, unlike today's oceans which typically have six levels of predators.
A new species of duck-billed dinosaur, Ahshislesaurus wimani, was discovered in New Mexico, dating back about 75 million years. The fossil, initially misclassified, was re-examined and identified as a distinct species, adding to the diversity of Late Cretaceous dinosaurs in North America and highlighting the region's rich paleontological history.
Scientists discovered a 95-million-year-old tiny skull of a previously unknown crocodile-like creature named Elton in Montana, revealing a new extinct family of small crocodyliforms with unique teeth and behaviors, providing insights into ancient ecosystems and convergent evolution.
Scientists in China used laser vaporization to directly date dinosaur eggs from the Late Cretaceous period, providing more precise age estimates and insights into dinosaur evolution, extinction, and environmental changes during that era.
Scientists discovered 112-million-year-old prehistoric insects preserved in amber in Ecuador, providing new insights into ancient ecosystems and the early interactions between flowering plants and insects during the age of the dinosaurs.
Scientists discovered South America's first large amber deposit in Ecuador, containing well-preserved insects and plant remains from over 100 million years ago, providing new insights into ancient ecosystems and rainforest environments during the Cretaceous period.