3d simulation of extinct biomes

[Bringing Fossils to Life]

The features of Ageleodus are inferred based on other early sharks, because we only have teeth from Red Hill and Poland, as stated in the post. In fact, this very reconstruction is based very closely off of a reconstruction by Jason Poole (these links: (https://www.anspblog.org/hyneria-lindae-part-1/ ) & (https://www.anspblog.org/illustrating-a-devonian-predator-part-2/)). Interestingly, these posts also disprove my Hyneria reconstruction. When you update your Ageleodus, don't forget the sharp tooth-like scales that all sharks have.

 

Here is a very quick diagram of early neocephalopod cross-sections of the cephalic area. It was made for my reference, so I added more diagrams and outlined a couple details to that it is hopefully easier for others to understand. It depict an Orthocerd (top), a Bactritid (bottom), and a hypothesized transitional form. The diagrams are in the style of Dzik (1981). Dzik has been criticized numerous times on his phylogeny and his soft tissue reconstructions don't make sense with today's knowledge of cephalopods (Dzik thought that cephalopod jaws originated from an operculum of a gastropod-like mollusk, so all of his palcephalopods had jaws), but his drawings of cephalopod shells come in handy (when they are obviously based on fossils). It's worth noting that Orthocerida is thought to have been weak swimmers, ancestrally vertical pelagic drifters, based on muscle scars, shell orientation studies, and color patterns. Later Orthocerids show color patterns like the above reconstructions, suggesting a more horizontally oriented life, moving towards Bactritida. Bactritida is thought to have been more active, based on muscle scars, and was primarily horizontal (based on its ability to pump liquid to its more posterior chambers thanks to its ventral siphuncle and its color patterns suggest this too). The increase of metabolism is thought to be in correlation with the diversification of fish, throughout history being Cephalopoda's biggest competitor (in the Cambrian, though, it was the Arthropods and not the fish). Don't mind the numbered lines on the drawing. I hope this is helpful!

Edited November 28, 2022 by Bringing Fossils to Life

[ftlcgi]

On 11/28/2022 at 5:37 PM, Bringing Fossils to Life said:

Here is a very quick diagram of early neocephalopod cross-sections of the cephalic area.

Thank you, this is a big help for me

I'm going to post the progress of the update here , right now it's a work in progress, and after i'm done i'l update the other models.

[Bringing Fossils to Life]

Remember that the Aptychopsis is almost big enough to cover the aperture - this is the basis of both the operculum theory that Greenfield supports (this is the previous style of reconstruction, with the Aptychopsis on top of the head), and the reconstruction I made based on the paper lined above. In this scenario the Aptychopsis evolved to protect the Orthocerids that were starting to become predatory instead of simply filter feeders from the prey they were otherwise not protected from. Also remember that on a whole Orthocerida is primarily vertical in orientation, or at least reverting to this position when not active, and a backwards (in a horizontal view ventrally) pointed hyponome would be the best way to swim, even if weakly. Thus the hyponomic sinus that you rightly reconstructed. The arm crown is pretty long, similar to the arm traces left by the closely related Actinocerida, but they were both horizontal and benthic, like cuttlefish today. I would shorten it to be only a little bit longer than the rest of the head. I have enclosed a quickly drawn figure of how I see Orthocerida progressing towards Bactritida, but since it includes unreleased material I made it tiny so as not to give it away completely yet. It shows my speculation to how different Orthocerida were oriented, the bigger icon representing dominant behavior and the smaller one behavior seen less often. In the late Ordovician, non-mineralized hard or tough plates arise (hypothesized, no fossils of this), then in the early mid Silurian, they become mineralized (fossil record shows this), and in the early to mid Devonian they become more recognizable as Neocephalopod jaws. They quickly change to fit the coiled form and different lifestyle of the ammonoids but take a different path that gives the end product of looking more similar to the nautilus's jaws in coleoidea. Most of this is my speculation, but we do have aptychopsis, evidence of bactritid jaws similar in shape to the ones I drew, ammonoid jaws, and (much later) coleoid jaws.

 

Edited November 30, 2022 by Bringing Fossils to Life

[Bringing Fossils to Life]

Also, could you add the radula? Sorry for all the critiques.

[rocket]

well done! I found this topic some minutes ago and enjoy to read and see your work. Are your illustrations free to use?

I ask because we have some large Calamophyton from lower devonian of germany and look for nice illustrations about it

[ftlcgi]

7 hours ago, rocket said:

Are your illustrations free to use?

Yes you can, i can send you some more so you can choose which ones you like

[ftlcgi]

On 11/30/2022 at 12:17 AM, Bringing Fossils to Life said:

Also, could you add the radula? Sorry for all the critiques.

Hi, here is a repost of the model with the changes but viewed as a section, i think i got most of the features, i'm going to finish the textures later (i added just some basic colors for now)

i made the internal parts using your drawing as a reference, i'm not going to ad any teeth to the radula right now i'l decide later on on how to make them

Edited December 4, 2022 by ftlcgi

[Bringing Fossils to Life]

Much better. The triangular upper valve ("upper jaw") is a little too curved, but the size of the Aptychopsis is good. Remembering that these are not technically jaws but protective plates may help. We know the Bactritids had functional jaws based on the injuries they gave each other. The external surface was smooth and calcified, not showing growth lines, at least in middle and late Silurian Aptychopsis (earlier ones in the early Silurian did not have the smooth calcitic layer). This is an inaccuracy in my own reconstruction; the calcitic layer makes preservation more likely, and the absence of Aptychopsis in Devonian rocks might be explained by them not being calcified. There is no evidence that I know of concerning the color pattern you used on the shell; longitudinal bands, the dorsal zig-zags seen on the (Outdated) reconstructions on my website, or zig-zags around the whole shell should do. Rosettes have been found on Endocerids, but not Orthocerids - this makes sense when you look at their interpreted niches. Red eyes make for a (probably unrealistic) scare!

 

Turek, of the operculum theory, figured the outer layer in his argument for Orthocerid operculums. In A most of it has cracked off. From Turek, V. (1978). Biological and stratigraphical significance of the Silurian nautiloid Aptychopsis. Lethaia, 11(2), 127-138.

Edited December 4, 2022 by Bringing Fossils to Life

[ftlcgi]

10 minutes ago, Bringing Fossils to Life said:

concerning the color pattern

that is just a placeholder texture, i didn't had time to finish it, it's going to have the same color pattern as before with the zig zag lines.

I thought they were used as jaws, that's why i made it like that

Edited December 4, 2022 by ftlcgi

[Bringing Fossils to Life]

I'm sorry I wasn't more clear about the function. Modern cephalopod jaws are homologous with Aptychopsis, but Aptychopsis, at least in a recent study I linked above, were not actively used to puncture and process food but to protect the soft cephalopod from their new prey. In Bactritida, as stated above, the plates were starting to be used as modern cephalopod jaws are, and I speculate the two lateral valves were fused together at this stage. Since early Ammonoids did not have calcified jaws, the Bactritids might not have either, not needing the defense as much as their metabolisms sped up, they grew more muscular, and could have simply swam away from danger more easily.

[Bringing Fossils to Life]

Concerning radular teeth, some were preserved in a "Michelinoceras". This is one of the reasons we think they were related to the coleoids and ammonoids.

https://sci-hub.se/https://link.springer.com/article/10.1007/BF02986061

Don't mind the "elongated tentacles," they don't have any other arms to compare them to and are likely just decomposing bits of the mantle, like in this paper.

https://www.nature.com/articles/s42003-019-0523-2

[ftlcgi]

1 hour ago, Bringing Fossils to Life said:

Concerning radular teeth, some were preserved in a "Michelinoceras". This is one of the reasons we think they were related to the coleoids and ammonoids.

thank you for taking the time to help me with the details, i'm going to study this papers, i had no ideea that there is so much info available

[ftlcgi]

I made a new eurypterid for the Hunsrück Slate biome, it was found some hundred km far from the site but it's from the same time period

Carcinosoma was a large eurypterid, as long as 2.5m, i used the old Adelophthalmus model as a template, it's still a work in progress, i'l post a render when it's done but you can view the progress here

[ftlcgi]

Two stylonurine eurypterids, these ones were more adapted for walking instead of swimming, found 70-100km from bundenbach, i would like to ad them to the Hunsrück Slate biome

 

[ftlcgi]

The largest arthropod that ever existed

[ftlcgi]

And a very small one, about 7.5cm long

[ftlcgi]

Another small eurypterid

[karelchytil]

Looks great, what sw areyou using?

[ftlcgi]

2 hours ago, karelchytil said:

Looks great, what sw areyou using?

thank you, I'm making the model in Blender using a drawing as reference.

After that i unwrap the uv's in UVLayout, it's a simple but very good tool and makes this process fun.

For texturing i'm using Substance painter

The animations are also made in blender

[Bringing Fossils to Life]

Where do you get your textures from? They look incredibly detailed.

[ftlcgi]

26 minutes ago, Bringing Fossils to Life said:

Where do you get your textures from? They look incredibly detailed.

i'm making them in substance painter, the textures are not hard to make, i just learned how to use the program better now

[ftlcgi]

there are some missing details that need be added and some that i got wrong and need fixing

- on the belly there are book gills similar to those in a horshoe crab

- all eurypterids have six pairs of appendages and besides jaekelopteris all are missing the first pair used for feeding (the chelicerae)

- the swimming animation should be a front to back movement like this,

http://www.lifebeforethedinosaurs.com/2011/07/eurypterus.html

 

[ftlcgi]

I managed to ad the book gills and the chelicerae to this Erieopterus model

 

[SomethingIsFishy]

Why is this literally the greatest thing I have ever seen!

[ftlcgi]

I had some free time and retextured some of the older models, some will need improvents on the mesh to

Orsadesmus - https://sketchfab.com/3d-models/orsadesmus-rubecollus-wip-18769400a73e4fe7a1c57a1885f25dcc

 

 

Bothriolepis - https://sketchfab.com/3d-models/bothriolepis-canadensis-bb6db6246ef04bd591f7840146bfb33b

 

I upgraded to a new and more powerfull PC, the old one was not capable of running the latest Unreal Engine and i'm testing some features that were unavailable before, i made some renders using the new engine version but it will take a bit of time before i learn how to take advantage of the new rendering technology

 

Edited December 29, 2022 by ftlcgi