If you were to look inside your mouth (I hope) you would see four different types of teeth: the incisors, canines, premolars and molars. As omnivores with varied diets, humans need these different types of teeth to eat. Our molars are used for chewing, crushing and grinding the food which has been gripped, torn and sliced by the incisors, canines and premolars. Like the animal kingdom itself animal teeth are incredibly varied in their shape and size, making them a fascinating topic of study. Today’s specimen comes from an animal with fewer types of teeth than humans, but considerable size to make up for it. Without further ado let’s get our teeth into this week’s Specimen of the Week…

Infant elephant molar, Elephas maximus LDUCZ-Z250

(more…)

LDUCZ-V1467 Moroccan phosphate fossil label

This week’s Specimen of the Week is not one, but 48 individual specimens which make up a display box highlighting various fossil teeth from Morocco. Display boxes of this sort are not uncommon as they are a visually appealing way to showcase numerous small specimens not to mention an entrepreneurial solution to add value to otherwise inexpensive individual fossils. The Grant Museum’s display box is a rather nice example of this type containing fossil teeth of 19 different species of fish and marine reptiles: (more…)

North American beaver skull. LDUCZ-Z2731

It is purely coincidence that Specimen of the Week 230 – the number most associated with going to the dentist [tooth hurty. Apologies.] – is an animal famous for the incredible feats of its teeth.

Beavers can cut down huge trees, owing to the superb adaptations of their skulls.

Like squirrels, but at the bottom of trees

As members of the squirrel-like rodent group Sciuromorpha, beavers have massive, ever-growing, self-sharpening front teeth. Rodent incisors are often differently coloured on the front and back. The orange substance on the front side is super hard enamel, while the back is unusually exposed dentine (a softer material which fills the inside in most teeth). When rodents bite on hard material, or even by biting their top teeth against their bottom teeth, the dentine erodes away at a faster rate than the enamel, essentially sharping the “blade”. (more…)

Crocodiles and alligators are big nasty predators. All of them. (Except the ones that are small lovely predators). If you see one swimming towards you then be concerned. Whilst considering your impending doom, you may wish to ascertain the correct taxonomic position of the beast. Here’s a quick guide to help you tell the difference between crocs and gators…

An Australian freshwater crocodile. One of the smaller lovelier ones (a baby) (C) Jack Ashby

Before that, I should explain that there are 23 members of the order Crocodylia, which contains both the crocodile family (Crocodylidae) and the alligator family (Alligatoridae), as well as the gharial (the sole member of the family Gavialidae). When I say “crocodile” I am referring to members of Crocodylidae, not all members of Crocodylia, otherwise there wouldn’t be much point to this post.

Things to ask to work out whether you are being eaten by a crocodile or an alligator… (more…)