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MULTITUBERCULATE CRETACEOUS AGE MAMMAL MOLAR Hell Creek Formation - Carter County, Southeastern Montana, U.S.A. LATE CRETACEOUS PERIOD: 75 - 65 million years ago From the Upper Cretaceous deposits of the famous Hell Creek dinosaur beds, we offer a rare specimen from an early mammal. This is a tiny fossil tooth from a small primitive mammal that scampered beneath the feet of some of the Earth's largest and most feared dinosaurs of the Cretaceous. This animal was a small rodent and belongs to the species Mesodma. While very tiny indeed, this fossil tooth is highly rare and specimens such as this are seldom found in private ownership. A fantastic specimen to display alongside dinosaur fossils offering an educational and intriguing addition to any collection, either public or private.This is one extreme high quality example of a chewing molar from this species. The crown is beautifully preserved with no erosion or breakage. Each and every cusp is perfect and the design of this specimen very closely resembles a Mastodon tooth, albeit a 4.5mm one! Exceptional preservation includes most of the root - HIGHLY RARE for roots to be present in Mesozoic mammal teeth! NO RESTORATION AND NO REPAIR. The first mammals emerged during the Mesozoic Period (248 to 65 million years ago) in the Late Triassic, 220 million years ago. These early mammals never gained a dominant presence and broad diversity until the Miocene Period, 15 million years ago. Of the Mesozoic Period, most people are familiar with the widely popular reptiles, namely dinosaurs. What is not commonly known is that during the age of the dinosaurs, small mammals were present scampering about the land no larger than your typical mouse or rat. It was not until the end of the dinosaurs 65 million years ago, that land mammals began to diversify and gain in size to immense proportions. An interesting trait that early mammals developed is teeth with multiple cusps. This allowed for more efficient chewing, enabling the animal to extract higher nutritional benefit from its food. This in comparison to the simplistic peg, spike or knife-shaped teeth of the reptiles where food was swallowed whole. The precursors to mammals were mammal-like reptiles called Cynodonts. These hybrid type creatures had molars with three cusps in a row. The first true land mammals also had molars with three inline cusps and are called Triconodonts. Triconodonts are believed to have been carnivorous but it is possible they could have been insectivores. They ranged in size from a large cat to a small rodent and all died out at the end of the Cretaceous Period, 65 million years ago. Another group of Mesozoic land mammals are the Multituberculates. These animals first emerged in the Jurassic, 160 million years ago and survived the mass extinction in the Cretaceous, surviving all the way up until the Oligocene Period, 35 million years ago. Their dentition resembled a rat with large premolars and long, multi-cusped chewing molars. The Multituberculates were also the first mammals to live in trees like the modern squirrel. In the Northern Hemisphere during the Late Cretaceous, more than half of typical land mammalian species were Multituberculates. This group of Mesozoic mammals were the most diverse in size ranging from a very small mouse to a beaver. It is believed they were omnivorous. Other groups of early mammals include the Monotremes (egg-laying mammals that suckle their young) and the Eutherians also known as Placentals (presence of the placenta allows the mother to nourish the developing embryo in the womb without forcing a developmentally early birth). Both Monotremes and Eutherians first existed during the Cretaceous but are survived today. Most mammals living today are Eutherians including humans. Monotremes on the other hand are rare, survived by few animals such as the Duck-billed Platypus and Spiny Anteater of Australia. The end of the Cretaceous marks the end of the Mesozoic Era. Mammals survived this profound mass extinction where the dinosaurs could not. This new age is called the Cenozoic Era which begins after the Cretaceous, 65 million years ago. Into this age, mammalian diversity and size exploded. Cenozoic translates into "new life" and best describes the amazing new creatures that this era was about to bring. INCREDIBLY RARE IN THIS QUALITY - HIGHEST GRADE WITH COMPLETE CROWN & PARTIAL ROOT! 4.5 millimeters in length SOLD LMM-003 INCLUDES DISPLAY BOX Actual Item - One Only |
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