What was the biggest "pre-dinosaur" animal?

[CalMeacham]

@JKellyMap

Mmmm, them’s good eatin’! “Red Eurypterid, for the seafood lover in you…”

Neat post, and well done remembering. Also others’ posts on Rhizodus, and on Dunkleosteus. I actually wrote a fifth-grade essay on the latter. Not 50 years ago, but close enough.

Yeah, I forgot about Dunkleosteus, which I grew up calling Deinichthys – “Terrible Fish”. I’ve seen pictures of skulls that were as high as a person, which indicated a fish many times more than 2 meters long.

[The_Peyote_Coyote]

Thanks for the posts, everyone. I’ve gotten some great ideas for my D&D campaign. I love prehistoric critters, especially if they’re big enough to eat characters.

[gytalf2000]

@The_Peyote_Coyote

Thanks for the posts, everyone. I’ve gotten some great ideas for my D&D campaign. I love prehistoric critters, especially if they’re big enough to eat characters.

That’s right! Predation is cool…

[Sailboat]

@CalMeacham

Yeah, I forgot about Dunkleosteus, which I grew up calling Deinichthys – “Terrible Fish”. I’ve seen pictures of skulls that were as high as a person, which indicated a fish many times more than 2 meters long.

Wikipedia offers some explanation of that particular confusion [which I shared, by the way]:

Dinichthys herzeri is an extinct, giant, marine arthrodire placoderm from the Late Devonian (Famennian stage) of Ohio and Tennessee. It was comparable in size, shape and ecological role to the better known Dunkleosteus. Originally described in 1868 by John Newberry on the basis of an incomplete skull roof and mandibles (AMNH 81), this species remains imperfectly known to this day.

For much of the 20th century, many unrelated large arthrodires were classified together within this genus, including species now assigned to Dunkleosteus, Eastmanosteus and Titanichthys. Today, Dinichthys is considered a monotypic genus, containing only the type species, D. herzeri. Similarly, in a 2010 analysis, the family Dinichthyidae that once held a wide range of arthrodire genera was redefined as comprising only Dinichthys.[1]

The type species of Dunkleosteus was originally described as Dinichthys terrelli by Newberry in 1873. After complete exoskeletons of this species were discovered in the early 20th century[2] Din. terrelli served as the basis for life reconstructions of the genus as opposed to the fragmentary Din. herzeri, even long after terrelli was separated into Dunkleosteus by Jean Pierre Lehman in 1956. As a result, most illustrations captioned as Dinichthys are actually pictures of Dunkleosteus.[3]

The article comes complete with a detailed technical illustration of the sort of quality and clarity I would have been proud of when I was 8. It is not to be missed.