Wednesday Wonders: Deinogalerix

20 08 2009

Good tidings and well-wishes!

Size, like many things, is relative. I realize that this isn’t the most scientific of statements presented on this blog, however it’s no secret that what we define as ‘massive’ or ‘huge’ may seem minute at a larger scale. A goldfish will tower over a school of guppies, while our own sun is minuscule compared to such stars as Antares, V354 Cephei, and VY Canis Majoris as shown by this quite humbling video. This observation applies particularly well to this week’s featured critter,Deinogalerix: an enormous hedgehog from the boot-heel of modern Italy.

Before discussing this great Erinaceomorph, it’s necessary to examine the creature’s native environment. During the late Miocene when this creature lived, the Adriatic coast of Italy witnessed the formation of an archipelago riddled with small islands including the forerunner of modern-day Monte Gargano. Each of these islands began to sprout its own endemic fauna composed primarily of hedgehogs and cricetids among other small mammals. However, as Jordi Augusti and Mauricio Anton explain in their superb book “Mammoths, Sabertooths, and Homonids: 65 Million Years Of Mammalian Evolution In Europe”, “The term ‘small mammals’ seems inappropriate when applied to the Gargano faunas, since, as insular forms, most of them were quite large.”

A perfect example of the inadequacy of this term is Deinogalerix sp. According to Kenneth Rose in “The Beginning Of The Age Of Mammals”,

“The Erinaceomorpha includes the hedgehogs (Erinaceidae) and at least five early Tertiary families, as well as several genera unassigned to families…The only living erinaceomorphs are the erinaceids, small insectovorans restricted to the Old World today but present in North America throughout much of the Tertiary. Living erinaceids range from mouse-sized to a little larger than the muskrat OndatraThe largest erinaceid, Miocene Deinogalerix, was considerably larger, with a body the size of the badger Taxidea and a skull as big as the coyote Canis latrans.”

Deinogalerix koenigswaldi skeleton in the Leiden Museum of the Netherlands.

Deinogalerix koenigswaldi skeleton in the Leiden Museum of the Netherlands.

Augusti and Anton have noted the animal’s close taxonomic proximity to Lantanotherium and write

Deinogalerix…had a body length of about 75 cm and a skull of 25 cm…It displayed an elongated face with long jaws and a short brain case. In the jaws, the upper incisors were procumbent [(“not upright in posture”)] and more insectivore-like, being followed by a pair of large lower canines.”

Deinogalerix reconstruction.

Deinogalerix reconstruction.

Despite these insectivore-like adaptations, Deinogalerix overall size suggests that it was primarily a predator of small vertebrates (though I doubt it would hesitate to devour a spineless meal on occasion if given the chance). The beast’s limb proportions suggests that it was incapable of obtaining particularly fast speeds (at least not regularly), which rules out the possibility of a carnivoran-like lifestyle reconstruction regardless of its considerable dimensions. For a more likely interpretation, we turn once again to Augusti and Anton:

“It was a predator that probably fed on small vertebrates by serching among litter and vegetation. The blunt shape of the cheek-teeth, capable of crushing hard carapaces, also suggests that Deinogalerix supplemented its diet with crabs and other shallow-water crustaceans, as its relative Echinosorex does today.”

Though it can’t be denied that this animal must have been a predator to reckon with, the hedgehog wasn’t without its own stalkers, namely Tyto gigantea, an enormous barn owl which rivaled the modern Eurasian eagle owl (Bubo bubo) in size. Currently, five species (D. koenigswaldi , D. minor , D. intermedius ,D. freudenthali, and D. brevirostris) of Deinogalerix are recognized, all of which hail from the Gargano island, which suggests that the genus may have exclusively resided in this fascinatingly alien region of the world.

May the fossil record continue to enchant us all!




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