So far, I’ve kept this thread to groups of fishes from modern bony fishes that are considered to be ‘primitive’, in either features or paleobiogeographic history. Now I’m including fish figures that I have of groups of non-bony fishes. Most of them have no living lineage—the placoderms, the acanthodiians, and the vast majority of the agnathans. I am including various people or other-animal models as scale references—it will become clear that many of these animals were very, very small. And a few were very, very large!
One many of the figures are shown with the Bullyland salmon, because I messed up. Just pretend it is a Bullyland trout (Salmo trutta
, (which would be about 16cm in real life) which is what I meant to do. Otherwise, the scales are fairly close to the modern fish or people they are shown with.
I will break it into two threads—first, the two jawed groups (gnathostomes) that are both entirely extinct, and work to the more primitive (and long-lived!) agnathans in a follow up post!ACANTHODII
: ”Spiny Sharks”
Probably the smallest group of totally-extinct fishes, these small fishes represent a group of fish that, in some form, led to the chondrichthyans—the sharks, rays and chimaera (plus their extinct relatives). For this reason, the group is sometimes referred to as “stem-sharks”.
Taxonomically, the Acanthodii is a paraphyletic group, since it does not include all of its descendants (the chondrichthyans), but instead acts as a convenient group to describe these fish. Overall, they are distinctive for their scales (similar to those of gars); streamlined bodies, heterocercal tails and stout spines on the leading edge of their fins (hence, the name ‘spiny sharks’). Also notable—many had several extra pairs of spined fins along their bellies.
Found in deposits around the world, the earliest fossils date from the Silurian (with some potential scales from the Ordovician) in marine waters, they diversified into freshwater and swamps in the Devonian and Carboniferous, and the group went extinct at the end of the Permian (~250Ma).
As far as toys go…there aren’t many. Two, to be exact. One has shown up many times; the sets it comes in makes me think Prior may be the original source (although I haven’t seen one) and can be found in several colours—I have seen grey, pink and green (and I had brown ones as a kid). The other, a more curved one cast entirely in solid plastic, is from US Toys and has shown up in bright pink and bright green (I only have the pink one).[You must be registered and logged in to see this image.]
All of these represent a version of Climatius
, but lack the belly spines are not paired, just a single row.
Front L-R: 1 version of the grey model; the pink version (I had one other once—the paint was completely different).
Back L-R: Other version of grey model; hot pink USToys model
Aaaaannnddd…that’s it. I am not aware of any others. Maybe a 3d printed one somewhere?PLACODERMIPlated Jawed Fish
Sort of like the Acanthodii, placoderms are also paraphyletic—because it is likely that, as a group, their descendants include the bony fish (which means they include the tetrapods—so instead of thinking of yourself as a lungfish descendant, think of yourself as a Bothriolepis
Placoderms were a very diverse if short-lived group of fishes, found around the world from the Silurian (~430Ma) to the Devonian (~360 Ma). In that time they diversified into somewhere between 7 and 10 distinct orders, with a wide range of shapes, habits, habitats, diets and sizes. In fact, one of them is famous for it’s size—Dunkleosteus
, the most famous placoderm, may have reached over 30 metres long (it’s an estimate—all that is known is the ridiculous skull) and it was probably the first true giant pelagic predator in the seas. But at the same time, a closely related species (Titanichthys
) was a similar size, but was probably a filter feeder—getting to that niche several hundred million years before the first filter feeding whales!
But most are small, and were possibly cumbersome, bottom-hugging animals. Their heavy body plating was likely a good defense, but may have also been a detriment when faced with predators (take note of their short time on earth—they disappeared as sharks and large bony fish began to arrive, either as predators or competitors).
Not all groups are represented as figures (only 3 from what I have). And only a very few taxa are represented as figures.Antiarchi
A strange group of heavily armoured placoderms, often with jointed, plated fins.[You must be registered and logged in to see this image.]
Three versions of Bothriolepis
, from Kaiyodo:
Front L-R: Purple Dinotales Series 1 version; Brown Dinotales Series 1v2 version; CapsuleQ Paleozoic series version on base.Rhenanida
A even stranger group of placoderms, which had armour made up of a mosaic of small scales or tubercles that may not have been fused. As a group, these placoderms were flattened like rays and patrolled sea bottom habitats.[You must be registered and logged in to see this image.]
The only one I know of--Gemuendina
, from Shapeways, unpainted.Arthrodira
The group that most people think of when they think of placoderms. IF they do, I suppose.
The group as a whole is identified by a joint in their armour between their head and their neck. This allowed them to not only open their jaw, but to tilt back their skull at the same time, giving a larger bite surface. And it was quite a bite—as with all placoderms, they didn’t have teeth. Instead, they used sharpened plates around their mouths as slicing surfaces!
As mentioned, Dunkleosteus
is easily the best known of the arthrodires (and placoderms) but overall this is the most diverse order of placoderms, many of which are quite small, and they ranged in seas, in diverse niches, around the world. This diversity began in the earliest Devonian, and the group was extinct by the end of the Devonian (~415Ma – 360Ma).Rolfosteus
A tiny, long-nosed placoderm![You must be registered and logged in to see this image.]
To scale with a Brown trout (if I’d used it…) Rolfosteus
only got to 15 cm long! This one is from the Yowies Lost Kingdom series.Variety of smaller arthrodires
There are a very few other models of other arthrodires, generally mid-size species that, while active, were not likely as predatory as Dunkleosteus
. These are to scale with a Bullyland Powan, a European whitefish that can get up to 38cm.[You must be registered and logged in to see this image.]
Clockwise from bottom left: Yowies Lost Kingdom Mcnamaraspis
; Yowies Lost Kingdom Groenlandaspis
; Prehistoric Panorama Coccosteus
(it is id’d as a Dunkleosteus, but the skull just doesn’t really look enough like one) ; Prehistoric Panorama Groendlandaspis
(although it kind of looks more like Bothriolepis
in some ways).Dunkleosteus
The big one—both in real size, and in figure form. I know that I don’t have every one of these, and I’m okay with that! This is the first placoderm model where it was possible to have them line up against human scale models. Although it is interesting, it’s good that it went extinct.[You must be registered and logged in to see this image.]
Kaiyodo Dinotales Series 7 skull[You must be registered and logged in to see this image.]
Kaiyodo Dinotales Series 2 (it is notable that Japanese models tend to use the lunate tail fin of a large, fast predator, instead of the more typical long, pointed tail fin of the smaller arthrodires).[You must be registered and logged in to see this image.]
The new Schleich model (complete with sturgeon-like scutes that have never been found on an arthrodire, and a jaw that opens, but doesn’t allow the skull to also lift. Missed opportunity Schleich).[You must be registered and logged in to see this image.]
L-R Favorite Soft Model on base; the Wild Safari Dinos & Prehistoric Life model (probably still the best representation overall—including painting the head to look like it was covered in skin that matched the rest of the body, instead of some heavy helmet of bone!)
As I said, there are several other models of Dunkleosteus
—Sean Cooper made a model, there is an even bigger Favorite vinyl model, and Kaiyodo made a new skull as part of it’s Paleozoic series. There is also an Animal Kaiser figure, a few Shapeways/3D models, and my son even has a tiny one in a snow globe!
So until next time, when the Agnathans make their appearance!***BONUS MESSAGE as I'm doing this, I thought I'd mention my 'wants' thread--where I am especially looking for a couple of fish, including the Panini lamprey and the new Yowies pupfish. Just throwing that out there! Even if someone in Europe is thinking of getting the Panini set, but would be willing to give up the lamprey!***