Thread by @FabioAleRomero

Finally, after months of waiting and a little more getting used to drawing placoderms, I finished my new version of Dunkleosteus, one of the most iconic animals of the Devonian and the Paleozoic, referred to as one of the first megafauna predatory vertebrates 1/

Although its full length has been an enigma due to the lack of a full specimen, which made lot of researches to rely on calculation and comparison with other more complete placoderms with varied results ranging sizes from 4 to 8 and even 10 meters. 2/

But as everybody has been aware over the last weeks a more rigorous study has been published on calculation methods that can almost accurately predict the length of Dunkleosteus and also being tested alongside other species of fishes for consistency on the results. 3/

Orbit-Opercular Length is the new method tested to obtain more precise measurements of body size which seems to be more precise with fusiform body shapes which Dunk falls on and with outliers like elongated body forms having more unstable results. 4/

I cannot comment much on the reliability of the data, as well I still have some time trying to learn how to do the calculations of what the paper present, so far I'm waiting for more qualified people opinion if this method can hold up or is defective in a sort of way. 5/

But I can't deny something I have noticed, from a while and now with the discovery of Amazichthys and that placoderm with some of their organs well preserved and in retrospective with other placoderms postcranial seems that these were always short body animals. 6/

No matter the species seems that in general the body cavity ended just shortly from the pelvic region which always is located after the ventral plates, and then depending of the taxon there might be variations of tail size and mostly the ventral size and the pattern repeat 7/

and I'm mentioning this because in retrospective a lot of reconstructions of Dunkleosteus have been assuming that the body cavity extended beyond the boundary of the ventral plates with the pelvic bones quite apart of the ventral plates to accommodate larger size measurements 8/

besides that, in recent years have appeared photographs of those specimens alongside accesible models with better scales and have made it easier to create a much better size scale which have allowed some better measurements of the skull and body shield 9/

I think about that given the current proportion of the ventral plates alongside a hypothetical position of the pelvic region the body cavity would have been very short probably being beneficial that the body was also quite deep to accommodate organs as 10/

this leaves the tail as that mysterious part that might we need further complete material to get a proper size estimation with concrete evidence, in that regard there is still room to elongate the caudal region with a limit (maybe just fluke, give it a thresher size one :B) 11/

I'm quite surprised how much has surface over the last 3 years regarding the reconstruction this animal more that I could have ever imagine, and I think thanks to social platforms and more research have brought a totally new form for this bizarre Devonian predator 12/

oh forgot the references
mdpi.com/1424-2818/15/3…