Madrid, 16 (European press)
The giant Kinyang dwarf crocodiles (shown in gold) were four times longer than their modern relatives, the dwarf crocodiles (shown in green). The discovery of the new species comes after the analysis of the skull of Kinyang’s specimen.
Pygmy crocodiles rarely exceed five feet in length, but ancient forms were up to four meters in length and were probably among the fiercest threats to any animal they encountered.
“These were the largest predators our ancestors encountered,” Christopher Brochu, a professor in the Iowa Department of Earth and Environmental Sciences and corresponding author of the study, says in a statement. “They were opportunistic predators, just like today’s crocodiles. It was absolutely dangerous for ancient humans to go to the river for a drink.”
The new species are called Kinyang mabokoensis and Kinyang tchernovi. They had a short, deep nose and large conical teeth. Their noses flared slightly up and forward, not as straight as in modern crocodiles. They spent most of their time in the forest, not in the water, waiting to ambush their prey.
“They had what looked like a big smile that made them look so happy, but they’ll kill your face if you give them the chance,” says Brocho.
The Kinyang lived in the East African Rift Valley, in parts of present-day Kenya, from the early to mid-Miocene, a time when the area was largely covered with forests. However, at the beginning of the end of a period called the Miocene climate optimum, about 15 million years ago, both species seemed to have become extinct.
Why did they disappear? Brochu believes that climate change has caused less rainfall in the area. Decreased rainfall has led to a gradual retreat in the forests, giving way to grasslands and mixed savannahs. The change in the landscape affected Kinyang, which researchers believe likely favored forest areas for hunting and nesting.
“Modern pygmy crocodiles are found exclusively in forested wetlands,” says Brocho, who has studied ancient and modern crocodiles for more than three decades. “The loss of habitat may have caused a major change in the crocodiles in the area.
“These same environmental changes have been linked to the emergence of larger, bipedal primates that led to the emergence of modern humans,” Brochu adds.
Brochu acknowledges that the cause of Kinyang’s extinction requires further testing, as researchers cannot determine when the animals became extinct. Moreover, there is a gap in the fossil record between Kinyang and other lineages of crocodiles that appeared on the scene about 7 million years ago. Among the new arrivals were relatives of the Nile crocodile, now in Kenya.
Brochu examined the samples during several visits since 2007 to the National Museums of Kenya, in Nairobi. The study was published in The Anatomical Record.
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