Updated July 22, 2021
note that adding taxa moves Andrewsarchus and Rhynchocyon a node away from tenrecs.
All we know of Andrewsarchus
is its skull — without a mandible. A few days ago the dentary of a sister taxon, Sinonyx, was added to the skull of Andrewsarchus ((Osborn 1924; middle Eocene, 45 mya; AMNH 20135; 83cm skull length; also see Fig. 1) just to see if it would fit.
everyone forever has always fleshed out Andrewsarchus like a giant bear/dog, moving the eyeballs to the top and giving it a bear/dog nose. Image googling “Andrewsarchus“ will give you an idea what a widespread and accepted tradition that has been. I even followed that tradition back in 1989 in the book Giants, which you can see here as subset 1 of a larger pdf of the entire book.
Andrewsarchus does not nest with bears, dogs or mesonychids. It nests with tenrecs and Rhynchocyon (Fig. 2.), one type of elephant shrew. (The other type of elephant shrew is unrelated, as we learned here, Fig. 2). Tenrecs have a long flexible nose.
So, here, without further adieu
is a first shot at adding tenrec soft tissue to the skull of Andrewsarchus (Fig. 1). Is it close to being correct? I hope so, given the present evidence.
Now, just imagine the post-crania…
and the best clue we have is the living tenrec, Rhynchocyon (Fig. 2) with long legs, robust torso and short tail, only ten times bigger.
Maybe it’s time to
give up the bear-dog restoration for Andrewsarchus and give it the giant tenrec restoration it deserves based on phylogenetic bracketing and phylogenetic analysis.
Osborn HF 1924. Andrewsarchus, giant mesonychid of Mongolia. American Museum Noviattes 146: 1-5.