Post by dinosauria101 on Mar 18, 2019 9:16:00 GMT 5
Sardinian Dwarf Mammoth - Mammuthus lamarmorai
The Sardinian dwarf mammoth (Mammuthus lamarmorai) is a species of mammoth which lived during the late Middle and Upper Pleistocene (between 450,000 and perhaps 40,000 years) on the island of Sardinia. M. lamarmorai is a dwarf species. This pygmy mammoth has been found mostly in the fine-grained sediments of the western part of the island. There is a great deal of fossil material known for M. lamarmorai, which includes cranial, dental, and post-cranial findings. So far, no complete skeleton is known. The length of the femur indicates a shoulder height of 1.4 m. The weight of this dwarf mammoths probably not have been more than 550 kg. The small size of M. lamarmorai is due to a process of insular dwarfism, which occurred when its original large ancestors reached Sardinia and due to lower food supply and lack of potential predators they reduced their size. As a mammoth, M. lamarmorai's closest living relative is the modern Asian elephant (Elephas maximus). The occurrence of this mammoth already in the late Middle Pleistocene makes that a descent from the classic woolly mammoth (M. primigenius) rather unlikely, since this latter species first appeared in Europe during the Upper Pleistocene. Rather, it is thought that the steppe mammoth (M. trogontherii), which lived on the continent, is the likely ancestor of M. lamarmorai. The origin of M. lamarmorai is still relatively unclear – the earliest finds date from the late portion of the Middle Pleistocene, as points their association with the dwarf deer Praemegaceros cazioti, and are thus about 450,000 years old. A colonization of Sardinia through the steppe mammoth should therefore be carried out in the transition from the old to the Middle Pleistocene or early Middle Pleistocene. This likely happened during the Pleistocene glacial periods in which the global sea level was much lower due to the continental ice sheets and the animals could reach the island by swimming.
Shaochilong maortuensis
Shaochilong (meaning "shark toothed dragon") is a genus of carcharodontosaurid dinosaur from the mid Cretaceous (Turonian stage) Ulansuhai Formation of China (about 92 million years ago). The type species, S. maortuensis, was originally named Chilantaisaurus maortuensis, but was re-described and reclassified in 2009. The holotype, IVPP V2885.1-7, consisting of skull fragments, axis and six caudal vertebrae associated to a single individual is the only known specimen. This specimen was discovered in Outer Mongolia and described by Hu in 1964 as a species of Chilantaisaurus. Chure (2002) and Rauhut (2001) suggested that it did not belong to that genus, and was probably a primitive coelurosaur. However, a re-description by Brusatte and colleagues in 2009 found that it was in fact a carcharodontosaurid, the first recognized from Asia. The genus was originally informally named "Alashansaurus". IVPP V2885.1 was probably adult or nearly adult individual. Its length – based on the length of the maxillary tooth row – is estimated at 6 metres (20 ft). Estimated length of the femur is 61.5 cm, what suggests that whole animal weighted approximately 500 kilograms (1,100 lb).
Credit to Wikipedia
The Sardinian dwarf mammoth (Mammuthus lamarmorai) is a species of mammoth which lived during the late Middle and Upper Pleistocene (between 450,000 and perhaps 40,000 years) on the island of Sardinia. M. lamarmorai is a dwarf species. This pygmy mammoth has been found mostly in the fine-grained sediments of the western part of the island. There is a great deal of fossil material known for M. lamarmorai, which includes cranial, dental, and post-cranial findings. So far, no complete skeleton is known. The length of the femur indicates a shoulder height of 1.4 m. The weight of this dwarf mammoths probably not have been more than 550 kg. The small size of M. lamarmorai is due to a process of insular dwarfism, which occurred when its original large ancestors reached Sardinia and due to lower food supply and lack of potential predators they reduced their size. As a mammoth, M. lamarmorai's closest living relative is the modern Asian elephant (Elephas maximus). The occurrence of this mammoth already in the late Middle Pleistocene makes that a descent from the classic woolly mammoth (M. primigenius) rather unlikely, since this latter species first appeared in Europe during the Upper Pleistocene. Rather, it is thought that the steppe mammoth (M. trogontherii), which lived on the continent, is the likely ancestor of M. lamarmorai. The origin of M. lamarmorai is still relatively unclear – the earliest finds date from the late portion of the Middle Pleistocene, as points their association with the dwarf deer Praemegaceros cazioti, and are thus about 450,000 years old. A colonization of Sardinia through the steppe mammoth should therefore be carried out in the transition from the old to the Middle Pleistocene or early Middle Pleistocene. This likely happened during the Pleistocene glacial periods in which the global sea level was much lower due to the continental ice sheets and the animals could reach the island by swimming.
Shaochilong maortuensis
Shaochilong (meaning "shark toothed dragon") is a genus of carcharodontosaurid dinosaur from the mid Cretaceous (Turonian stage) Ulansuhai Formation of China (about 92 million years ago). The type species, S. maortuensis, was originally named Chilantaisaurus maortuensis, but was re-described and reclassified in 2009. The holotype, IVPP V2885.1-7, consisting of skull fragments, axis and six caudal vertebrae associated to a single individual is the only known specimen. This specimen was discovered in Outer Mongolia and described by Hu in 1964 as a species of Chilantaisaurus. Chure (2002) and Rauhut (2001) suggested that it did not belong to that genus, and was probably a primitive coelurosaur. However, a re-description by Brusatte and colleagues in 2009 found that it was in fact a carcharodontosaurid, the first recognized from Asia. The genus was originally informally named "Alashansaurus". IVPP V2885.1 was probably adult or nearly adult individual. Its length – based on the length of the maxillary tooth row – is estimated at 6 metres (20 ft). Estimated length of the femur is 61.5 cm, what suggests that whole animal weighted approximately 500 kilograms (1,100 lb).
Credit to Wikipedia