Armored Mammals: the Cingulata order

The Giant Armadillo (Priodontes maximus)

We boldly continue armor week with an overview of the magnificent armadillo family.  This order of armored mammals (Cingulata) is more diverse than any other sort of armored mammals–outshining even the scaled pangolins. Today the only living members of the Cingulata order are the armadillo family (a successful group consisting of more than 20 living species) but the armadillos’ extinct cousins were once far more widespread and bizarre.  These relatives included the pampatheres–long plantigrade browsing creatures covered in banded armor who roamed the continent from one end to the other.  Even more impressive were the glyptodonts, massive tank-like creatures bigger than a compact car.

A fossil glyptodon, fossil pamphathere, and armadillo skeleton (in the far right corner)

The Cingulata order is part of the superorder Xenarthra. Separated from all other placental mammals for over 100 million years (due to South America’s unique isolation after the breakup of the southern supercontinent Gondwana), xenarthrans evolved in different directions from other mammals. The unique challenges and opportunities of their island continent resulted in bony domed giants like the pampatheres and glyptodonts, both of which are characterized by tortoise-like body armor composed of bone segments (osteoderms).  The glyptodonts were unlike tortoises in that they could not draw their head beneath their shells: instead their heads were protected by bony caps atop their skulls. The largest glyptodonts could grow to 4 metres long, 1.5 metres high and have a mass of 3 tons (Ferrebeekeeper has already written about the smallest known Cingulata species—the pink fairy armadillo, which can still be found living in the central dry lands of Argentina).

Glyptodon

Thanks to convergent evolution the herbivorous glyptodonts resembled other armored giants like cryptodire turtles and ankylosaurs.  One species of glyptodont, Doedicurus clavicaudatus, even had a heavy spiked tail (although it is unclear whether this was used against predators or to compete for territory and mates).

Doedicurus clavicaudatus

When the first members of the Cingulata order emerged in the Myocene, the top predators of South America were giant running predatory birds–the Phorusrhacidae, which resembled giant dashing eagles up to 3.2 metres (10 ft) high.  The glyptodonts, pampatheres, and armadillos outlasted these terror birds and they then outlasted the carnivorous metatherian mammals (with terrible saber teeth) which followed.  When the Isthmus of Panama connected South America with North America (and therefore with an entirely new universe of ultra-competitive mammals), the armored cingulatans competed just fine with the newcomers.  Some glyptodonts and pamphatheres wandered up through Central America and found new homes in North America.  The armadillos are still there.  However at the end of the last ice-age, a new African species arrived and brought a devastating and final end to the glyptodonts, the pampatheres, and most of the armadillos. But even this newly arrived predator seemed impressed by the greatest of armored mammals.  An Argentine anthropologist even reports discovering a site twenty leagues from Buenos Aires where early human hunters had used glyptodont shells as dwelling places.

Human Hunters Stalk a Glyptodon (Heinrich Harder)

The Pink Fairy Armadillo

Pink Fairy Armadillo (Chlamyphorus truncates)

There are twenty extant species of armadillos–new world placental mammals covered with armored plates. The smallest of these armored creatures is the Pink Fairy Armadillo (Chlamyphorus truncates) which is only 9-12 centimeters in total length (about 4 or 5 inches).  The diminutive creature weighs slightly more than 100 grams when mature and inhabits the central drylands of Argentina.  It has multiple hard ring-like plates of delicate pink which it can close into a box form for protection (although its first defensive strategy is to dig into the ground).  The animal has tiny eyes and a torpedo-like head for pushing into the sand. The portions of the Pink Fairy Armadillo not covered with plates are covered in dense white fur. Like the golden mole of Namibia, the pink fairy armadillo is a sand swimmer:  the little animal agitates the fine, dry sand with its powerful claws and literally swims through the turbulence with its hard bullet shaped body.  The armadillos are also like the golden mole in that they can lower their metabolism to levels unheard of among other placental mammals.  However armadillos are not closely related to the golden mole—or indeed to any other placental mammals other than fellow Xenarthra (the sloths, armadillos, and anteaters).  South America spent a long portion of geological time as an island and the mammals there had a long time to develop on their own.  It is still not known whether Xenarthrans like the Pink Fairy Armadillo are truly Eutherians or whether they are the descendants of the ancestors of the Eutherians (sorry: the language of cladistics does not lend itself to eloquent explanations and all of the names sound like they come from a far-away planet—for example “Xenarthrans”).

I would like to tell you more about the Pink Fairy Armadillo, but I am unable to do so.  Since it lives underground, the animal is rarely seen in the wild.  It is even more unusual in captivity where it does not long survive the shocks and stresses of zoo living (additionally it seems unable to live on anything other than local invertebrates). This is unfortunate as it is believed that the Pink Fairy Armadillo is struggling in the wild.  It is presumed to be declining in numbers–a victim to habitat loss from human activity.  I used wiggle words like “believed” and “presumed” because nobody really has any idea about the actual populations of Pink Fairy Armadillos.

In the absence of real information here is a little gallery of Pink Fairy Armadillo artwork.  Enjoy these pictures, it is profoundly unlikely you will ever see a real Pink Fairy Armadillo in the real world (which is sad because I find them curiously endearing). I particularly like the cartoon of the Pink Fairy Armadillo dreaming of transcendence into a mythical fairy being.

Drawing by Frohickey

Digital Artwork by Loba Feroz

Art by Guertelmaus

Sculpture by Michelle de Bruin

Cartoon by Blade Zulah