Here my brand new necklace.
Fox canine tooth
Have nice winter holidays. I’m out to celebrate.
I know what you’ll think. “Another photoset? Will this girl ever write anything again? Why did you burn my toast?”
But this one is for all you thylacine lovers.
This real-bone skull of Thylacinus cynocephalus is on display at the Oxford University Museum of Natural History and I took the pictures when I went there with my family two weeks ago. These were, sadly, the only angles I could get without breaking my neck, but they still let you appreciate what a marvel of convergent evolution this skull is. At first look there are definitely more similarities to your typical canid skull than there are differences.
The first and most obvious thing is the dentition, in particular the lack of pronounced carnassials. Another thing that is easy to spot, and is in my opinion the definitive way of telling if an animal is a marsupial once you know what to look for, is the presence of the two gaping holes on the posterior side of the palate (third photo). These are palatal vacuities and all marsupials have them. Another, less obvious, feature in the larger depth of the masseteric fossa (A simple legend can be found here http://anatomy.wikispaces.com/Mandibular+fossa) and the breadth of the two sides of the mandible as seen from below, where a bony shelf is formed (fourth photo).
I will leave the rest of the difference-spotting fun to you. You can find a useful, if small, comparison chart here: http://images2.fanpop.com/image/photos/10800000/Thylacine-skull-and-skeleton-thylacine-10824820-432-588.jpg
This turned out longer than expected! Hope you like it.
Epicyon haydeni - the largest dog
When: Mid to Late Miocene (~20 to 5 million years ago)
Where: Throughout much of North America, excepting northern Canada.
What: Epicyon haydeni is the largest canid known. It is estimated to have weighed in at roughly 375 lbs (~170 kg). Even though it was the size of a bear, it still retained the relatively long legs and resulting fast speed that characterizes dogs. These dogs were not just ‘scaled up’ wolves, they were much more solidly built in general and had teeth more adapted for bone crunching. While they were top predators, and perhaps hunted in packs, they were no doubt also scavengers - able to crush bone in order to eat what had been left behind by other hunters.
Epicyon is a genus in the clade Borophaginae. This is one of the three major subclades of the dog family. The last common ancestor of the borophagines and the modern canines lived over 30 million years ago. While this subclade is characterized by large bone crushing dogs, it also contained dogs which more more resemble living forms such as the wolf. In the reconstruction image the large dog is Epicyon haydeni and the smaller is another member of the same genus. On the whole, borophagines were more omnivorous than their canine relatives.