Post by DinosaurMichael on Jul 25, 2012 7:48:13 GMT -5
Nile Crocodile - Crocodylus niloticus
The Nile crocodile or Common crocodile (Crocodylus niloticus) is an African crocodile which is common in Somalia, Ethiopia, Uganda, Kenya, Egypt, Tanzania, Zambia, Zimbabwe, Gabon, South Africa, Malawi, Sudan, Botswana, and Cameroon. Isolated populations also exist in Madagascar, Senegal. The Nile crocodile is the largest crocodilian in Africa and is sometimes regarded as the second largest crocodilian after the saltwater crocodile. The male crocodile usually measure from 11.5 to 16 feet long (3.5 to 5 metres), but very old, mature ones can grow to 18 ft (5.5 m) or more. Like all crocodiles they are sexually dimorphic, with the males up to 30% larger than the females, though the difference is even more in some species, like the saltwater crocodile. Mature female Nile crocodiles measure 8 to 13 ft (2.4 to 4.0 m) Typical Nile crocodile weight is around 225 kg (500 lb), though large specimens can range up to 730 kg (1,600 lb) in mass. The largest accurately measured male was shot near Mwanza, Tanzania and measured 6.45 m (21.2 ft) and weighed approximately 1,090 kg (2,400 lb). 7-metre (23 ft) specimens and larger have been reported, but since gross overestimation of size is common these reports are suspect. The largest living specimen is purported to be a man-eater from Burundi named Gustave; he is believed to be more than 20 ft (6.1 m) long. Such giants are rare today; before the heavy hunting of the 1940s and 1950s, a larger population base and more extensive wetland habitats meant more giants. There is some evidence that Nile crocodiles from cooler climates like the southern tip of Africa are smaller, and may reach lengths of only 4 m (13 ft). Dwarf Nile crocodiles also exist in Mali and in the Sahara desert, which reach only 2 to 3 m (6.5 to 10 ft) in length. Their reduced size is probably the result of the less than ideal environmental conditions, not genetics.
Megalania - Varanus priscus
Megalania ("great roamer"; Greek Μέγας "great" + ἀλαίνω "roam") is a giant extinct goanna or monitor lizard. It was part of a megafaunal assemblage that inhabited southern Australia during the Pleistocene, and appears to have disappeared around 40,000 years ago. The first aboriginal settlers of Australia may have encountered living Megalania. The name Megalania prisca was coined by Sir Richard Owen to mean "Ancient Great Roamer"; the name was intended to "reference to the terrestrial nature of the great Saurian". Owen used a modification of the Greek word ἠλαίνω ēlainō ("I roam"). The close similarity to the Latin word: lania (feminine form of "butcher") has resulted in numerous taxonomic and popular descriptions of Megalania mistranslating the name as: Ancient Giant Butcher. Megalania prisca was originally classified in its own monotypic genus. Its status as a valid genus remains controversial, with many authors preferring to consider it a junior synonym of Varanus, which encompasses all living monitor lizards. As the gender of the genera Megalania and Varanus are different (feminine and masculine, respectively), the epithet prisca changes to priscus (in alignment with the Code of the ICZN). Several studies have attempted to establish the phylogenetic position of Megalania within the Varanidae. An affinity with the Perentie, Australia's largest living lizard, has been suggested based on skull-roof morphology. The most recent comprehensive study proposes a sister-taxon relationship with the Komodo dragon based on neurocranial similarities, with the Lace monitor as the closest living Australian relative. Conversely, the Perentie is considered more closely related to the Gould's and Argus monitors. The lack of complete, or nearly complete fossil skeletons has made it difficult to determine the exact dimensions of Megalania. Early estimates placed the length of the largest individuals at 7 metres (23 ft), with a maximum weight of approximately 600–620 kilograms (1,300–1,400 lb). However, more recent and more rigorous studies give very different results from one another. In 2002, Stephen Wroe determined that Megalania had a maximum length of 4.5 metres (15 ft) and a weight of 331 kilograms (730 lb), while its average length would have been around 3.5 metres (11 ft), and mean body weight would have been between 97–158 kilograms (210–350 lb). He concluded that the earlier estimates reaching lengths of 6 metres (20 ft) or more and a weight of several tons were exaggerations based upon flawed methodologies. However, Ralph Molnar in 2004 determined a range of potential sizes for Megalania (made by scaling up from dorsal vertebrae, after he determined a relationship between dorsal vertebrae length and total body length). If it had a long thin tail like the Lace monitor (Varanus varius), then it would have reached a length of 7.9 metres (26 ft), while if its tail-to-body proportions were more similar to that of the Komodo dragon, then a length of around 7 metres (23 ft) is more likely. Taking the maximal 7 m length, he estimated a weight of 1,940 kilograms (4,300 lb), with a leaner 320 kilograms (710 lb) being average.
The Nile crocodile or Common crocodile (Crocodylus niloticus) is an African crocodile which is common in Somalia, Ethiopia, Uganda, Kenya, Egypt, Tanzania, Zambia, Zimbabwe, Gabon, South Africa, Malawi, Sudan, Botswana, and Cameroon. Isolated populations also exist in Madagascar, Senegal. The Nile crocodile is the largest crocodilian in Africa and is sometimes regarded as the second largest crocodilian after the saltwater crocodile. The male crocodile usually measure from 11.5 to 16 feet long (3.5 to 5 metres), but very old, mature ones can grow to 18 ft (5.5 m) or more. Like all crocodiles they are sexually dimorphic, with the males up to 30% larger than the females, though the difference is even more in some species, like the saltwater crocodile. Mature female Nile crocodiles measure 8 to 13 ft (2.4 to 4.0 m) Typical Nile crocodile weight is around 225 kg (500 lb), though large specimens can range up to 730 kg (1,600 lb) in mass. The largest accurately measured male was shot near Mwanza, Tanzania and measured 6.45 m (21.2 ft) and weighed approximately 1,090 kg (2,400 lb). 7-metre (23 ft) specimens and larger have been reported, but since gross overestimation of size is common these reports are suspect. The largest living specimen is purported to be a man-eater from Burundi named Gustave; he is believed to be more than 20 ft (6.1 m) long. Such giants are rare today; before the heavy hunting of the 1940s and 1950s, a larger population base and more extensive wetland habitats meant more giants. There is some evidence that Nile crocodiles from cooler climates like the southern tip of Africa are smaller, and may reach lengths of only 4 m (13 ft). Dwarf Nile crocodiles also exist in Mali and in the Sahara desert, which reach only 2 to 3 m (6.5 to 10 ft) in length. Their reduced size is probably the result of the less than ideal environmental conditions, not genetics.
Megalania - Varanus priscus
Megalania ("great roamer"; Greek Μέγας "great" + ἀλαίνω "roam") is a giant extinct goanna or monitor lizard. It was part of a megafaunal assemblage that inhabited southern Australia during the Pleistocene, and appears to have disappeared around 40,000 years ago. The first aboriginal settlers of Australia may have encountered living Megalania. The name Megalania prisca was coined by Sir Richard Owen to mean "Ancient Great Roamer"; the name was intended to "reference to the terrestrial nature of the great Saurian". Owen used a modification of the Greek word ἠλαίνω ēlainō ("I roam"). The close similarity to the Latin word: lania (feminine form of "butcher") has resulted in numerous taxonomic and popular descriptions of Megalania mistranslating the name as: Ancient Giant Butcher. Megalania prisca was originally classified in its own monotypic genus. Its status as a valid genus remains controversial, with many authors preferring to consider it a junior synonym of Varanus, which encompasses all living monitor lizards. As the gender of the genera Megalania and Varanus are different (feminine and masculine, respectively), the epithet prisca changes to priscus (in alignment with the Code of the ICZN). Several studies have attempted to establish the phylogenetic position of Megalania within the Varanidae. An affinity with the Perentie, Australia's largest living lizard, has been suggested based on skull-roof morphology. The most recent comprehensive study proposes a sister-taxon relationship with the Komodo dragon based on neurocranial similarities, with the Lace monitor as the closest living Australian relative. Conversely, the Perentie is considered more closely related to the Gould's and Argus monitors. The lack of complete, or nearly complete fossil skeletons has made it difficult to determine the exact dimensions of Megalania. Early estimates placed the length of the largest individuals at 7 metres (23 ft), with a maximum weight of approximately 600–620 kilograms (1,300–1,400 lb). However, more recent and more rigorous studies give very different results from one another. In 2002, Stephen Wroe determined that Megalania had a maximum length of 4.5 metres (15 ft) and a weight of 331 kilograms (730 lb), while its average length would have been around 3.5 metres (11 ft), and mean body weight would have been between 97–158 kilograms (210–350 lb). He concluded that the earlier estimates reaching lengths of 6 metres (20 ft) or more and a weight of several tons were exaggerations based upon flawed methodologies. However, Ralph Molnar in 2004 determined a range of potential sizes for Megalania (made by scaling up from dorsal vertebrae, after he determined a relationship between dorsal vertebrae length and total body length). If it had a long thin tail like the Lace monitor (Varanus varius), then it would have reached a length of 7.9 metres (26 ft), while if its tail-to-body proportions were more similar to that of the Komodo dragon, then a length of around 7 metres (23 ft) is more likely. Taking the maximal 7 m length, he estimated a weight of 1,940 kilograms (4,300 lb), with a leaner 320 kilograms (710 lb) being average.
