Family of the Week: The Hedgehogs

The hedgehogs are pretty widespread in the old world Metazoic. I have retained the modern day family name, Erinaceidae, and even have a few modern genera stretch into the Metazoic era. Some species take dramatic turns. There are still several spiny species that walk along the ground and curl up into a spiky ball when they are threatened. However, there are spineless species that seek their safety in the treetops or in underground burrows. They range in size from the tiny, mouse-sized Neotetracus, to Pithecurus, which can measure about 3 feet including the tail. They still retain the same dental features of their modern counterparts. The elongated incisors seem to be what separates them from other insectivores, and is present even in exclusively Metazoic species. Most species are active only at night, with the exception of Echinosorex, Hylomys, Neotetracus, and Neohylomys. At night, these animals recover to their underground burrows, or ground-level tree hollows. Some species, such as Pithecurus, Dendroechinus, Gliropetes, and Sylvericus, are nocturnal tree-dwellers. Pithecurus has even developed a prehensile tail to aid in grasping tree branches as it runs. These species have no spines at all, and unlike the gymnures and their spikeless, ground-dwelling allies, have no odorous scent gland to use as defense. Their primary defense is remaining in the trees and moving quickly. All species are found only in the Old World. There are no species that can be found in the New World, not even in the Metazoic.

There are 2 sub-families in the Metazoic; the Erinaceinae contain the modern genera, and the Pithecurinae contain the tree-dwellers. Most of the Erinaceinae are tail-less, or have very short tails. The Pithecurinae on the other hand, have tails usually longer than their head and body, or at least of equal length. Some have developed prehensile tails, but none to the degree of Pithecurus, who has the strongest tail in the family. The legs are generally short in all but Pithecurus, whose legs are not really long, but better designed for leaping. All hedgehogs and relatives walk in a plantigrade fashion. That is, they walk on their palms and soles. A few species, like those of Erinaceus, are hibernators, and usually go to underground burrows, or hollow logs, to roost in a torpid state. However, the species E. amurensis, does not hibernate, but rather sits out the cold spells, and has developed a woolly coat between the spiny coat.

Erinaceids are omnivorous. Most of their diet consists of insects, small vertebrates, bird eggs, carrion, fruit, berries and even flowers. Erinaceids, even today, are uniquely immune to such things as snake venom. This is an advantage as such animals as Pithecurus dispatches small, tree-dwelling vipers. Pithecurus is among the most carnivorous and vicious of all Erinaceids. They feed on not only snakes, but lizards, birds, bats, eggs, mice, sometimes they will even descend to the ground to hunt small antelope, like Quadroculus. Despite it's ability to see in all directions at once, it often gets caught and killed by Pithecurus, which then carries it into the trees to be consumed. Pithecurus also sometimes will kill small lemurs, like the bushbabies, and eat them. They are agile enough to persue bushbabies, though they cannot always leap as far as the bushbabies can. But for their size, Pithecurus can leap as far as 15 feet in a single bound. Other tree-dwelling Erinaceids have a mixed diet, with equal amounts of meat and fruit in their diet.

Whether the Erinaceids use spikes, bad odor, or agility as their means of defense, they can sometimes fall prey to a wide range of predators. Most among them, foxes, predatory rats and Regisciurids, and civets and mongooses. Metazoic genets are particularly skilled at unfolding hedgehogs that have taken up their defensive spiny ball posture, and getting to their head, which is then crushed in the predator's mouth. They seem to have an ability to ignore the sharp spines. Some predators, like the predatory pteropods, can even take the tree-dwelling species. Sometimes even Pithecurus. Tree-dwelling Erinaceids do not always roost in tree hollows, sometimes they roost out on a tree branch like sloths, which makes them even more vulnerable to attack from day predators. Pithecurus has large, sharp teeth, and curved claws, which gives them some defensive weaponry. But they rarely get the chance to use these weapons when confronting a predator like Nycteraptor.

Comments

Popular posts from this blog

The Making of Lemuria?

New Changes to Old Names

How Cities Affect Evolution