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16.01.2016 15:15 - Largest prehistoric animals Vol.1 Vertebrates part9 Reptilies ch.3 Crocodylomorpha - Crocodile
Автор: valentint Категория: Забавление   
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Последна промяна: 05.12.2016 19:24


Crocodylus bugtiensis

Crocodylus bugtiensis is an extinct species of crocodile that lived in Pakistan during the late Oligocene period.This reptile family of crocodiles found in the Oligocene-Miocene of Pakistan. Perhaps - the largest representative of his family, or even detachment.
Species that left teeth marks on the bones on paraceratherium, reached more than 10-11 meters in length. However, crocodiles tend to be about half or even twice as large as its normal production (example - the Nile crocodile and waterbuck and kudu large, estuarine crocodile and dugong or leatherback turtle). Thus, eating paraceratherium, C. bugtiensis probably could grow more than 15 meters in length, thereby competing in size with deinosuchus, puruszavrom, ramfozuhom and other large crocodiles antiquity.


Crocodylus thorbjarnarsoni

Crocodylus thorbjarnarsoni is an extinct species of crocodile from the Pliocene and Pleistocene of the Turkana Basin in Kenya. It is closely related to the species Crocodylus anthropophagus, which lived during the same time in Tanzania. C. thorbjarnarsoni could be the largest known true crocodile,[a] with the largest skull found indicating a possible total length up to 7.6 m (25 ft). It may have been a predator of early hominins. Crocodylus thorbjarnarsoni was named by Christopher Brochu and Glenn Storrs in 2012 in honor of John Thorbjarnarson, a conservationist who worked to protect endangered crocodilians.

Crocodylus thorbjarnarsoni is distinguished from other crocodiles by its broad snout. It has small raised rims on the prefrontal bones in front of the eyes, a feature also seen in some Nile crocodile individuals. The squamosal bones form raised rims along the sides of the skull table, similar to the crests in C. anthropophagus but much smaller. Also like C. anthropophagus, it has nostrils that open slightly forward rather than directly upward analysis for Crocodylus, this corresponds to a total length of 6.2–6.5 m (20–21 ft) but such analysis have been shown to underestimate the size of very large individuals by as much as 20%, w
The largest C. thorbjarnarsoni skull found (KNM-ER 1682) measures 85 cm (33 in) from the tip of the snout to the back of the skull table, in comparison, the largest known extant Crocodylus skull is that of a saltwater crocodile, measuring 76 cm (30 in). Based on regression hich means it could have been as long as 7.6 m (25 ft).
Crocodylus thorbjarnarsoni likely preyed on human ancestors like Paranthropus and early members of the genus Homo, both of which are known from the Turkana Basin. Direct evidence of crocodilian predation is known from bite marks on hominin bones from the Olduvai Gorge, and these marks were likely made by the closely related crocodile C. anthropophagus (anthropophagus means "human eater" in Greek). No hominin bones from the Turkana Basin bear crocodilian bite marks, so there is no direct evidence that C. thorbjarnarsoni preyed on hominins. However, modern Nile crocodiles are known to consume adult humans, and since C. thorbjarnarsoni was larger than any Nile crocodile, it easily could have eaten smaller-bodied human ancestors. Brochu and Storrs hypothesized that the lack of bite marks could have been due to hominin's awareness of crocodiles and ability to evade them, explaining that "this conflict—eat and drink, but maybe die—was presumably foremost amongst the concerns our predecessors felt when approaching ancient waterways inhabited by Crocodylus thorbjarnarsoni." Another explanation was that C. thorbjarnarsoni may have eaten hominins whole with little need for biting, since it was much larger.


Rimasuchus

Rimasuchus is an extinct genus of crocodile from the Neogene period of Africa and the Middle East. Its name comes from the Latin words rima, meaning "crack" (referencing the East African rift valley where it was discovered) and suchus, which means "crocodile".Rimasuchus is a member of the subfamily Crocodylinae, which includes over 20 species, eight of which are extinct. The type and only species, Rimasuchus lloydi, lived alongside other crocodiles such as the Nile crocodile. It preyed on large mammals, including early humans.

Rimasuchus grew to 7 meters or more in length. Unlike most living crocodiles, it is brevirostrine, or broad-snouted. Rimasuchus has characteristically short and broad premaxillae, as well as a deep mandibular symphysis connecting the two sides of the upper jaw. The premaxillae do not project as far back on the upper surface of the skull as those of other crocodiles and are noticeably wider than they are long on the palate (unlike those of Crocodylus niloticus and Crocodylus cataphractus). The external nares are positioned close to the tip of the snout. Like other crocodiles, Rimasuchus has an occlusal groove, or notch, between the premaxilla and maxilla that receives the fourth mandibular tooth. However, in Rimasuchus the groove is noticeably shorter anteroposteriorly than that of C. niloticus. The preorbital region is flat and there is no nasal promontorium, or raised nasal region, as in C. niloticus.
The teeth of Rimasuchus are robust and blunt, unlike those of other crocodiles. They become more bulbous toward the rear of the jaws. The crowns of the teeth are rarely sharp, although crown sharpness tends to lessen with size in crocodylians. The teeth are uniquely bicarinate, meaning that there are ridges on the front and back.
Remains of Rimasuchus show variations in size and proportions, and it is likely that they represent different ontogenic (growth) stages. There has been very little study so far on ontogenic variation in Rimasuchus and living crocodiles. There are many similarities between specimens of R. lloydi and C. niloticus, and it is likely that some specimens of Rimasuchus actually represent particularly large examples of C. niloticus.
Rimasuchus lloydi was first described in 1918 and originally placed in the genus Crocodylus under the name C. lloydi. After cladistic analysis suggested that it did not belong in Crocodylus, however, the new genus was erected in 2003. Among crocodylines, Rimasuchus is most closely related to the living dwarf crocodile Osteolaemus and is placed within the group Osteolaeminae.


 

Crocodylus anthropophagus

Crocodylus anthropophagus is a species of extinct crocodile that is part of the same genus as some of today’s living crocodiles such as the Nile (Crocodylus niloticus), Siamese (Crocodylus siamensis) and American (Crocodylus acutus) crocodiles amongst some others.  It was a large-sized apex predator reaching a length of 7.5 m (25 ft).C. anthropophagus however lived in Africa during the Plio-Pleistocene era when early hominids like Homo habilis and Paranthropus boisei lived in the area. Additionally some hominid fossils have been found with tooth marks that seem to have been left by crocodiles, something which led to the creation of the species name ‘anthropophagus’ which literally translated to English means ‘human eating’.
Although the remains of Crocodylus anthropophagus are very partial and incomplete, comparison to living crocs has led to size estimates approaching seven and a half meters long. If correct this would make C. anthropophagus slightly bigger than the largest recorded saltwater crocodiles (Crocodylus porosus), which are considered to be the largest living species of crocodile today. This has also led to suggestion that the tooth marks on hominid remains were left by juveniles as such large crocodiles would probably leave nothing of early hominids (which were much smaller than modern humans) for palaeontologists to later find. Despite this large size however, C. anthropophagus would have been puny when compared to truly giant crocodiles like Purussaurus from the earlier Miocene, or even Sarcosuchus from the Cretaceous.
Although incomplete, the snout of C. anthropophagus seems to have been much deeper than other species of Crocodylus such as the Nile Crocodile (C. niloticus). This more robust skull would have been better able to withstand the stresses of holding onto more powerful prey, and likely also allowed for more powerful bite muscles. Including the fossil evidence of early hominid predation, a picture comes together where just like crocodiles today smaller juveniles of C. anthropophagus hunted and killed smaller less powerful prey, while the older, bigger and more powerful individuals killed larger and more powerful animals.

 


NEW DISCOVERY-11.01.2016

Machimosaurus rex

Scientists unearthed the remains of a crocodile as big as a bus in Sahara desert. The bizarre crocodile is believed to have terrorized the sea nearly 130 million years ago. Dubbed as the largest sea crocodile discovered, animal experts and palaeontologists are excited with this new discovery.
A team of paleontologists led by Federico Fanti received a grant from the National Geographic Society Committee for Research and Exploration for their project. Fate was on their side as they discovered a fossilized skull and fragments of many skeletons buried in the desert.
"This is a neat new discovery from a part of the world that hasn't been well-explored for fossils," said Stephen Brusatte, a paleontologist at the University of Edinburgh.
The ancient reptile, Machimosaurus rex, could have grown to more than 30 feet long and weighed about 6,000 pounds. The skull alone is more than 5 feet long. It is now considered the largest sea crocodile discovered while the biggest freshwater crocodile, Sarcosuchus imperator, which lived around 110 million years ago, grew to 40 feet with a weight of 17,500 pounds.










 



 




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Автор: valentint
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