This 2016 video is called Origins of Genus Homo–Australopiths and Early Homo; Variation of Early Homo; Speciation of Homo.
From New Scientist:
Monster crocodile was ancient human nightmare
* 14:29 24 February 2010 by Ewen Callaway
A newly identified man-eating crocodile might have spawned more than its share of prehistoric nightmares.
Discovered in 1.8-million-year-old rocks from Olduvai gorge in Tanzania, the 7.5-metre Crocodylus anthropophagus would have been the largest predator ancient humans in the region encountered.
“I can’t guarantee these crocodiles were killing our ancestors, but they were certainly biting them,” says Chris Brochu, a vertebrate palaeontologist at the University of Iowa in Iowa City. Brochu gave the beast its name, which means “man-eating crocodile” in Greek: “I hope people get the joke.”
Ancient hominid bones discovered by Mary and Louis Leakey in the same sediments bear distinct bite marks likely to have been inflicted by large crocs. Yet most researchers have assumed the gashes were delivered by the same species of crocodile that prowls the banks of the Nile today.
Not so, claims Brochu, who re-analysed numerous incomplete fossils, the most recent of which was unearthed in 2007 by his co-authors Robert Blumenschine at Rutgers University in New Brunswick, New Jersey, and Jackson Njau of the National Natural History Museum in Arusha, Tanzania.
Lots of crocs
Though roughly the same size as the reptilian denizens of the Nile, the Olduvai crocodiles had thinner, more flared snouts and large horns that are more characteristic of a Madagascan crocodile that went extinct in the past few thousand years.
The discovery of C. anthropophagus points to far more diversity in African crocodiles in the past 2.5 million years than thought, Brochu says. “People have always perceived crocodiles as these slowly evolving, living fossils. That’s just nonsense.”
His team haven’t found many fossils belonging to C. anthropophagus, and none that is complete, so it’s impossible to determine its precise relationship to modern Nile crocodiles or when the man-eaters went extinct, Brochu says.
But he has little doubt that C. anthropophagus threatened the ancient hominids who called Olduvai gorge home and would have been drawn to a nearby source of fresh water. Adults of one species, Homo habilis, were particularly vulnerable, being only around a metre tall and weighing about 40 kilograms.
Their fossil cut marks, then, were probably delivered by smaller specimens of C. anthropophagus. Brochu’s team writes: “Larger crocodiles would be capable of consuming hominids completely, leaving no trace.”
Journal reference: PLoS One, DOI: 10.1371/journal.pone.0009333.
Remains of the enormous horned croc, named Crocodylus thorbjarnarsoni, were unearthed in East Africa. The impressive aquatic reptile exceeded 27 feet long and is described in the latest Journal of Vertebrate Paleontology: here.
Ancient crocodile mummies scanned at Stanford: here.
Cayman and butterfly photos: here.
After being hunted to the edge of extinction, the American crocodile’s U.S. population has rebounded to its highest level in more than a century: here.
June 2010. The mystery of how the world’s largest living reptile – the estuarine crocodile – has come to occupy so many South Pacific islands separated by huge stretches of ocean despite being a poor swimmer has at last been solved by a group of Australian ecologists who say that, like a surfer catching a wave, the crocodiles ride ocean currents to cross large areas of open sea: here.