Sunday, 9 August 2009
British Wildlife: E
Eotyrannus lengi Hutt, Naish, Martill, Barker & Newbery, 2001
Family incertae sedis; Saurischia; Sauropsida; Chordata
Eotyrannus is the only known genus of tyrannosauroid theropod, with the possible exception of Iliosuchus, to have been found in the UK*. It is believed to be an early ancestor (early Cretaceous in age) of the large tyrannosaurids, such as Tyrannosaurus itself, found in North America and Asia during the late Cretaceous. Eotyrannus ('dawn tyrant') would have looked somewhat like a smaller version of these familiar dinosaurs.
* I have been informed by Darren Naish (thanks!) that there is another British tyrannosauroid, Stokesosaurus, formerly known only from North America.
Eotyrannus lengi bones, including parts of the maxilla, mandible, rear portion of the skull, claws and limbs
Remains of the genus have so far been found only on the Isle of Wight. Close relatives occur in Portugal (Aviatyrannus), China (Dilong, Guanlong) and North America (Stokesosaurus). I've illustrated my Eotyrannus with feathers; it is known that the Chinese Dilong paradoxus was feathered, and it makes sense that other basal tyrannosauroids would have been similar.
Erinaceus europaeus Linnaeus, 1758
Erinaceidae; Eulipotyphla; Mammalia; Chordata
Several years ago, hedgehogs were a common sight in gardens and urban areas in the UK. I don't even mean a long time ago; I'm only 23 and I can remember seeing them in the garden on a weekly basis when I was a child. Nowadays, they are more commonly seen squished on the road.
European hedgehog found in Street, Somerset
The above individual, rolled in a ball for protection, is the first live Erinaceus europaeus I have seen in years. Hedgehogs are the most conspicuous of Britain's three types of insectivores (eulipotyphlans); the mole (Talpa europaea), although common, is rarely seen due to its subterranean habits; and the shrews are small, highly active, and often mistaken for mice or voles. Hedgehogs, although primarily nocturnal and crepuscular (active at twilight), often make an appearance in daylight hours as they are well protected by their spines, derived from thickened, sharpened hairs. Only the most determined foxes, badgers and dogs will risk a nose full of prickles to make a meal of an urchin. Hedgehogs carry out the most unusual behaviour known as self-anointing. They will froth at the mouth and lick this froth over their entire body. It is believed to make them distasteful to predators.
Skull of European hedgehog
It is easy to see the hedgehog's teeth in this photo of a skull. Hedgehogs have fairly unspecialised teeth. The cheek teeth follow the tribosphenic design. This is the triangular shape, when viewed from above, which is generally found in the most 'primitive' mammals. By 'primitive', I mean those which are close to the ancestral mammals. Young platypuses have tribosphenic molars, and lose them as they grow. Most insectivores also have them: they are great for crushing the hard exoskeletons of their arthropod prey.
Haliaeetus albicilla (Linnaeus, 1758)
Accipitridae; Falconiformes; Aves; Chordata
Britain has two types of eagle: the golden eagle (Aquila chrysaetos) and the white-tailed eagle. Neither are that closely related to each other; members of the genus Aquila are considered the classic eagles, with members across Eurasia, Africa and Australia, with the golden eagle spreading into North America as well. The genus Haliaeetus, however, are collectively known as the 'fish eagles' and are actually larger than the Aquila eagles. There are members in North America (the United States' emblem, the bald eagle, H. leucocephalus), Eurasia (including the immense Steller's sea eagle, H. pelagicus), Africa (like the African fish eagle, H. vocifer) and Australasia (including the white-bellied sea eagle, H. leucogaster). They habitually eat fish and catch them with incredible agility with their talons.
In the UK, golden eagles are found only in Scotland and northern England. They were formerly more wide-ranging. I have seen them on the island of Rum. The white-tailed eagle was extirpated from the UK, and has slowly been reintroduced to islands off western Scotland. There has been much public outcry, mainly from sheep farmers, who object to their reintroduction, as they are reported to take lambs. The culprits are more likely to be buzzards, as white-tailed eagles prefer fish. There are talks of releasing the white-tailed eagle to England, and it would be fantastic to see this huge raptor take to the English skies once more, like a giant flying barn door.
For F, prepare for a trilobite, a canid and a felid.