Episode One of “Ice Age Giants” Focuses on the Laurentide Ice Sheet
The BBC have put together a television series featuring the Mammalian “megafauna” of the Pliocene and the Pleistocene Epochs with a focus on the Ice Age – hence the title of the three-part series “Ice Age Giants”. The first episode was entitled “Land of the Sabre-Tooth” and focused on the impact of the immense Laurentide ice sheet on North America. With the assured Professor Alice Roberts, an anatomist (human anatomy that is), by training at the helm and undertaking the presenting duties the programme was up to the high standards expected of the BBC.
A Replica of a Smilodon
The first episode focused on a number of the large mammals that lived south of the two mile high Laurentide ice sheet that covered much of the continent, over thousand of years the ebbs and flows of the ice sheets led to the creation of some very rich and verdant plains and swamplands, these were home to an array of bizarre mammals, with only a few remnants of the Ice Age megafauna left today, animals such as the bison and the elk.
The Sabre-toothed cat, (Smilodon fatalis) was the star of the first programme with a focus on the latest theories about how those huge canines could have been used to kill prey. The CGI was not overplayed, although the scene in which a single cat chases down and catches a horse did not look particularly authentic to our team. Smilodon fatalis had immensely powerful arms and shoulders, this point was made in the documentary, however, the impact on this cat’s ability to run was not explored fully. Most certainly, these apex predators specialised in big game, but they probably were not out and out pursuit predators, but more likely to have been ambush predators having to get very close to any potential victim before launching an attack.
It is incorrect to refer to these members of the Felidae as “Sabre-Toothed Tigers” to read Everything Dinosaur’s explanation: Sabre-Toothed Cats not closely related to Extant Tigers.
The astonishing degree of preservation of the dung of the Shasta Ground Sloth (Nothrotheriops shastensis) and what the metre thick sediments found in caves in the Grand Canyon walls can tell us was the highlight. Dating techniques have permitted scientists to plot exactly when these cow-sized sloths abandoned the Grand Canyon area and when they returned. These results tie in very nicely with known ice age extensions and warmer inter-glacial periods. It is amazing what you can learn from a 20,000 year old ball of dung.
It was pleasing to see that a South American immigrant, a glyptodont was featured. Once thought of being a creature of the open plains, it seems that a substantial population thrived in the swamplands that once covered much of Arizona. The explanation as to why most glyptodont fossils are found upside down was interesting as was the the theory that these distant relatives of anteaters, sloths and armadillos may have had trunks.
An Illustration of a Typical Glyptodont
Picture credit: Everything Dinosaur
The polished faces of boulders being presented as evidence of these rocks being used as giant scratching posts as herds of giant Columbian Mammoth (Mammuthus columbi), was something new to us, we had not read about this in any literature. Most probably many animals used these outcrops as scratching posts over millenia, but the fourteen foot high polished areas could only have been made by something as big as a Columbian Mammoth. That said, this part of California has been subjected to sizeable earthquakes and the land may have been raised somewhat, especially with the retreat of the heavy ice sheets, so it has to be presumed for the Columbian Mammoth theory to be accepted then these rocks would have had to remain somewhat “in situ”.
Interesting to see the many fossils from La Brea Tar Pits, a part of Los Angeles that team members at Everything Dinosaur have been lucky enough to visit. The pathology, suspected sceptic arthritis on a pelvis and its potential implications on the social nature of Sabre-Tooths was very well explained. Intriguingly, there was no mention of the proposed Californian sub-species of Sabre-toothed cat. The tar pits at Rancho La Brea in Los Angeles have produced a lot of fossil material relating to the Smilodon genus (mainly S. californicus and not S. fatalis). Everything Dinosaur has followed the work on the material removed due to the building of the underground library car park with great interest since excavations began back in early 2011. We refer to the crates of sediment taken out as part of the ground works for the library as “box cart palaeontology”.
To read more about the “box cart” excavations at Rancho La Brea: Huge Haul of Ice Age Fossils from La Brea.
All in all, a promising start to this series and we are already looking forward to episode two.
To view the large range of prehistoric mammals models and figures stocked by Everything Dinosaur: Models of Prehistoric Mammals.