xenarthran

2

Doedicurus 

Skeleton on display at the Museo Histórico Nacional in Buenos Aires, Argentina. 

When: Pleistocene (2 million to 11,000 years ago)

Where: South America

What: Doedicurus is a glyptodont. The Glyptodontidae were a subclade of armadillos that ranged throughout South America (and North after the land bridge reappeared). Doedicurus was one of the largest glyptodons, coming in at about 12 feet (~3.6 meters) long. Its shell was gigantic, a grown person can crawl inside one of these structures, and there has been some theories that ancient peoples could have used these shells for shelter.  The shell of Doedicurus, like all glyptodonts, was different from that of the living armadillos. The carapaces were thicker and in one solid piece, unlike the several segments present in armadillos that allow them to curl into a ball. Doedicurus had a highly domed shell, that connected to its pelvis posteriorly, but was separated from its shoulder girdle. It has been speculated that glyptodons with this type of shell stored fat in this space above the shoulders, such as a modern camel stores fat in its hump. Doedicurus also had an armored skull cap, which you can see in the fossil image but sadly has been omitted from the reconstruction. 

One of the most distinctive features of Doedicurus is its spiked tail club. In most of these entries when I present something cool that you can imagine being used in intraspecific competition I have to say ‘but it was just for display or protection’. NOT THIS TIME. There is a great amount of evidence for the hypothesis that these spiked tail clubs were used in battles between males. Not all specimens of Doedicurus have a well developed pedestal for the spikes, leading researchers to conclude this was only present in males. It is very unlikely this would have been anymore of a deterrent for predators than the large shell in the first place, and just as unlikely that Doedicurus would have been agile enough to defend itself from a swift carnivorous attacker with this club. Most compelling of all, several Doedicurus specimens have been found with healed wounds in their carapaces that match the predicted impact from a rival’s tail club. 

Doedicurus, like all of the remaining glyptodonts, went extinct about 11-10,000 years ago, at the end of the last major glaciation. 

youtube

Bath time for baby sloths

Afrotherian (A,C–E,G,J,K) and xenarthran (B,H) embryos.

(A) African Elephant, Loxodonta africana (UMZC), (B) Southern Tamandua, Tamandua tetradactyla (ZMB 40639; anteater with placenta), © North African Elephant Shrew, Elephantulus rozeti (ZMB: Macroscelides 34a), (D) Rock Hyrax, Procavia capensis (UP: Hyrax), (E) Aardvark, Orycteropus afer (UP), (F) Giant Otter Shrew, Potamogale velox (ZMB: IN. 38), (G) West Indian Manatee, Trichechus manatus (BMNH 65.4.28.9), (H) Three-Toed Sloth, Bradypus spec. (ZMB 18835, Bradypus), (J) Cape Golden Mole, Chrysochloris asiatica (ZMB: N.N.), (K) Giant Otter Shrew, Potamogale velox (ZMB: IN. 44). Scale bars: (A,B,D,E,H–K) 1 cm, (C,F) 0.25 cm, (G) 10 cm. UP, University of Pretoria Collection; BMNH, British Museum of Natural History; ZMB, Zoologisches Museum Berlin.

Werneburg I, Tzika AC, Hautier L, Asher RJ, Milinkovitch MC, Sánchez-Villagra MR. 2012. Development and embryonic staging in non-model organisms: the case of an afrotherian mammal. Journal of Anatomy. DOI: 10.1111/j.1469-7580.2012.01509.x 
2

Peltephilus - The Horned Armadillo 

Skull located in the Museo Histórico Nacional, Buenos Aires, Argentina. 

When:Oligocene to Miocene (~29 to 15 million years ago)

Where: South America    

What: Peltephilus is a primitive armadillo. This is the only known armadillo with horns, and one of only two known horned fossorial (digging) mammals. The other is Ceratogaulus, a gopher that lived somewhat contemporaneously in North America. Like Ceratogaulus, the horns of Peltephilus were for defensive purposes, and were not useful in either digging or for battles between individuals. Peltephilus was once proposed to have been a fast running meat eating armadillo, but more recent and in-depth studies have countered these claims and instead demonstrated that this 3 feet (~1 meter) long armadillo was indeed a digging herbivore like most known armadillos.

Peltephilus is the basal most armadillo known. One of its most obvious primitive features is that it has a full compliment of teeth in the front of its mouth that contact one another. All other armadillos have reduced anterior dentition and thus ‘spouts’ at the front of the mouths. These front teeth were the source for the early ideas of carnivory in this species. Even though Peltephilus was primitive in this, and other cranial and skeletal features, it is still highly derived and, well, already armadillo like in many other aspects, most notably its well developed carapace. 

youtube

Have a noisy baby sloth

youtube

The Screaming Hairy Armadillo (Chaetophractus vellerosus) in action.

From National Geographic Photo Of The Day; May 24, 2013:

Giant Anteater, Brazil Gerardo Ceballos, Your Shot

“I took this shot of a Giant Anteater (Myrmecophaga tridactyla) in the Fazenda Barranco Alto, a 30,000-acre cattle ranch and wildlife preserve in the Pantanal of the Brazilian state of Mato Grosso do Sul. I had been looking for animals all day long, driving and walking through grasslands and forest patches that surround the endless lakes dotting the landscape of this region. During the day I had seen other giant anteaters, a giant otter, white-lipped peccaries, and many other interesting mammals. As the sun was setting, I saw a dark shadow on the shore of one of the lakes. I took my camera and walked slowly toward that moving shadow. With great surprise I found out that it was a giant anteater. I took the photo with a flash against the fading daylight. It was a memorable moment that was caught in my photo”. —Gerardo Ceballos

This photo and caption were submitted to Your Shot. Check out the new and improved website, where you can share and connect with fellow photographers from around the globe.