“R” is for Ragnarok

“R” is for Ragnarok

Ragnarok is proof that paleontologists have a sense of humor.

The name Ragnarok comes from Norse mythology. It is a series of events foretold for the future, that essentially brings about the demise of human kind by various natural phenomena, including global flooding. All that remains of humanity is two people, left to repopulate the world.

The reason Ragnarok gets its name is because it is a member of the Family Arctocyonidae, the ‘bear-dogs.’ Superficially, that’s what they look like: A cross between a bear and a dog.

Arctocyon, the type member of the Arctocyonidae. Credit: Dmitry Bogdanov, via Wikimedia Commons.

Arctocyonids were neither bears nor dogs, and probably weren’t even fully carnivorous, but their enlarged canines convey an image of power. They probably weren’t active hunters, but would jump on something convenient. Arctocyonids are better considered omnivores.

The Arctocyonidae are considered condylarths, a group of primitive mammals, which may or may not actually be evolutionarily related to one another. Arctocyonids may have been ancestral to the Mesonychids and/or the Cetartiodactyla, which may be ancestral to modern whales.

The genus Ragnarok is no longer considered a valid name. That is to say, it is now more proper to call mammals once assigned to Ragnarok members of the genus Baioconodon. Ragnarok is now relegated to ‘junior synonym’ status.  The name Ragnarok still survives in the literature, of course, from before it was synonymized with Baioconodon.

Upper teeth of Ragarok nordicum (now Baioconodon nordicum) from the Puercan North American Land Mammal Age (Earliest Paleocene) in Montana.

The upper teeth and lower teeth show the basic tribosphenic pattern of mammal teeth, with no particular specializations for carnivory.

Lower jaw of Ragnarok nordicum (now Baioconodon nordicum) from the Puercan of Montana.

Neither Ragnarok nor Baioconodon is known from The Breaks. But the name is worth mention.

Thanks to Darrin Pagnac for reminding me of this beast. It’s a perfect Paleocene “R” mammal!

Part of the Blogging from A to Z challenge

For 4-10-13


  1. Ciara Knight says:

    Fascinating! I am enjoying all the information you’ve provided.

    I’m a minion checking in. Great job. Keep going!!


  2. John Wiswell says:

    The artist’s rendering looks sort of like a seal, particularly in the face. I’d be intimidated by a confrontation, but I don’t know if it’d be the end of the world. Get it? End of the world?

    John at The Bathroom Monologues


  3. This is awesome! I had heard the name “Ragnarok” from mythology, but never knew of the mammal!

    Omnivores, you say?


    1. Penny says:

      Yeah. The teeth lack adaptations for pure carnivory. Check out tomorrow’s post on Viverravus for what carnivore teeth look like!


    1. Penny says:

      Ragnarok is from the Paleocene Epoch, Cenozoic Era. The Paleocene runs from ~65 million years ago (just when the dinosaurs went extinct), to ~55 million years ago.


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