This is Thrilling Wonder Stories for Spring 1944, cover by Earle Bergey. The ISFDB entry for this issue is here. I found this version of the cover at Pulp Covers. In addition to some interior art reproductions found at Pulp Covers, the issue also has this uncredited illustration for Manley Wade Wellman’s “Gambler’s Asteroid.”
You can download and read this issue at the Internet Archive.
They look more like walruses, or maybe those future walrus things from Primeval.
Yeah, I sort of agree. That’s in fact what I decided ex post when I tweeted about the image: