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|Topic Started: May 5 2012, 02:47 PM (1,122 Views)|
|Taipan||May 5 2012, 02:47 PM Post #1|
Temporal range: Pliocene - Pleistocene, 4.2–2.0 Ma
Species: 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 is the largest known true crocodile, and may have grown up to 7.5 metres (25 ft) in length. 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.
Based on the large size of C. thorbjarnarsoni skulls, the largest individuals of the species are estimated to have been around 7.5 metres (25 ft) in length. This estimate places C. thorbjarnarsoni as the largest known species of Crocodylus, larger than the biggest 6.4 metres (21 ft)-long Nile crocodiles.
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.
C. thorbjarnarsoni is known from nine skulls, all of which are housed in the National Museum of Kenya. The holotype is a nearly complete skull and lower jaw called KNM-ER 1683 and comes from the approximately 2 million-year-old Koobi Fora Formation on the eastern shore of Lake Turkana. The skulls KNM-ER 1681 and KNM-ER 1682 have also been found from the formation. Three other skulls are known from the Nachukui Formation, west of the holotype's locality. KNM-WT 38977 is from the 2.5 to 3.4 million-year-old Lower Lomekwi Member, KNM-LT 26305 is from the 3.9 million-year-old Kaiyumung Member, and KNM-LT 421 is from the 4.2 to 5.0 million-year-old Apak Member. Three additional skulls called KNM-KP 18338, KNM-KP 30604, and KNM-KP 30619 are known from the southern Turkana Basin in the Kanapoi Formation, dating between 4.07 and 4.12 million years. KNM-ER 1682, KNM-LT 421, KNM-LT 26305, and KNM-KP 30619 were previously assigned to Rimasuchus lloydi, and their reassignment to C. thorbjarnarsoni reduces the range of R. lloydi to Northern Africa.
A skull of the newfound crocodile species
Largest Known Crocodile Could Swallow a Human
The illustration shows the comparative sizes of ancient/modern crocodiles and ancient/modern humans.
ScienceDaily (May 4, 2012) — A crocodile large enough to swallow humans once lived in East Africa, according to a University of Iowa researcher. "It’s the largest known true crocodile,” says Christopher Brochu, associate professor of geoscience. “It may have exceeded 27 feet in length. By comparison, the largest recorded Nile crocodile was less than 21 feet, and most are much smaller.”
Brochu’s paper on the discovery of a new crocodile species was just published in the May 3 issue of the Journal of Vertebrate Paleontology. The new species lived between 2 and 4 million years ago in Kenya. It resembled its living cousin, the Nile crocodile, but was more massive.
He recognized the new species from fossils that he examined three years ago at the National Museum of Kenya in Nairobi. Some were found at sites known for important human fossil discoveries. “It lived alongside our ancestors, and it probably ate them,” Brochu says. He explains that although the fossils contain no evidence of human/reptile encounters, crocodiles generally eat whatever they can swallow, and humans of that time period would have stood no more than four feet tall.
"We don’t actually have fossil human remains with croc bites, but the crocs were bigger than today’s crocodiles, and we were smaller, so there probably wasn’t much biting involved,” Brochu says.
He adds that there likely would have been ample opportunity for humans to encounter crocs. That’s because early man, along with other animals, would have had to seek water at rivers and lakes where crocodiles lie in wait.
Regarding the name he gave to the new species, Brochu said there was never a doubt.
The crocodile Crocodylus thorbjarnarsoni is named after John Thorbjarnarson, famed crocodile expert and Brochu’s colleague who died of malaria while in the field several years ago.
“He was a giant in the field, so it only made sense to name a giant after him,” Brochu says. “I certainly miss him, and I needed to honor him in some way. I couldn’t not do it.”
Among the skills needed for one to discover a new species of crocodile is, apparently, a keen eye.
Not that the fossilized crocodile head is small—it took four men to lift it. But other experts had seen the fossil without realizing it was a new species. Brochu points out that the Nairobi collection is “beautiful” and contains many fossils that have been incompletely studied. “So many discoveries could yet be made,” he says.
In fact, this isn’t the first time Brochu has made a discovery involving fossils from eastern Africa. In 2010, he published a paper on his finding a man-eating horned crocodile from Tanzania named Crocodylus anthropophagus—a crocodile related to his most recent discovery.
Brochu says Crocodylus thorbjarnarsoni is not directly related to the present-day Nile crocodile. This suggests that the Nile crocodile is a fairly young species and not an ancient “living fossil,” as many people believe. “We really don’t know where the Nile crocodile came from,” Brochu says, “but it only appears after some of these prehistoric giants died out.”
The work was funded in part by the National Science Foundation and the UI Obermann Center for Advanced Studies.
Christopher A. Brochu, Glenn W. Storrs. A giant crocodile from the Plio-Pleistocene of Kenya, the phylogenetic relationships of Neogene African crocodylines, and the antiquity ofCrocodylusin Africa. Journal of Vertebrate Paleontology, 2012; 32 (3): 587 DOI: 10.1080/02724634.2012.652324
Edited by Taipan, May 11 2012, 03:50 PM.
|Taipan||May 8 2012, 02:42 PM Post #2|
Ancient Crocodile Was World's Largest
Date: 07 May 2012 Time: 02:31 PM ET
Scientists have announced the discovery of a newfound crocodile species that may have been the largest to ever roam the Earth. The colossal reptiles trolled East African waters between 4 million and 2 million years ago, and may have snacked on human ancestors, researchers said.
The largest fossil specimens recovered belong to massive crocodiles some 25 feet (7.5 meters) in length; and the ancient giants may have grown larger than 27 feet (8 meters), according to Christopher Brochu, an associate professor of geosciences at the University of Iowa.
Brochu stumbled upon the new species three years ago, while examining enormous fossils housed at the National Museum of Kenya in Nairobi. It took four men to lift the skull of one of the specimens, which were originally excavated from the Turkana Basin, an area surrounding Lake Turkana in northern Kenya.
The region is a famed hotspot for human fossil finds. Many early hominids have been unearthed from the Turkana Basin, and Brochu said it's possible some of them came to a nasty end, thanks to the prehistoric crocodiles, dubbed Crocodylus thorbjarnarsoni.
"It lived alongside our ancestors, and it probably ate them." Brochu said in a statement, adding that the colossal reptiles may have swallowed them whole.
"We don’t actually have fossil human remains with croc bites, but the crocs were bigger than today's crocodiles, and we were smaller, so there probably wasn't much biting involved," he said.
Brochu's research is published in the May 3 issue of the Journal of Vertebrate Paleontology.
The newfound species isn't closely related to Nile crocodiles, Brochu said. "We really don't know where the Nile crocodile came from," he said, "but it only appears after some of these prehistoric giants died out."
|DinosaurMichael||Jul 30 2012, 04:27 AM Post #3|
||I wonder how much this Crocodile would of weighed? From the looks of it. It would likely be a ton on average.|
Other sites I'm a member on.|
|Godzillasaurus||Jul 30 2012, 11:09 AM Post #4|
|I'm slightly puzzled. This animal, which looks a lot like an alligator, is in the crocodile family. And animals like deinosuchus which, in my opinion, look a lot more like crocs, are in the alligator family. AM I MISSING SOMETHING!?!?|
Long live the one and only King of Monsters, Godzilla!!!|
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