For this next entry in my jawless fish entry we have another one off creature, another enigma that unlike Tullimonstrum is still to this day fairly obscure even for the broader paleo community on the internet.
Palaeospondylus has no common name sadly but unlike with Tullimonstrum there were two species that were mostly the same outside of size and where they were found. P. gunni was found in Caithness Scotland while P. australis was found in well Australia. It would have been a small animal with the larges specimen reaching at most 2 inches. As you can guess by the title of this image and it's name it's taxonomy is heavily disputed. Initially it was thought of being the tadpole of some tetrapod or lungfish however a 2024 study analyzing the braincase found that to be not the case. Other hypothesis include it being an unarmored placoderm or a baby cartilaginous fish but the curren consensus indicates that it is a jawless fish. Some say it's a stem hagfish but this is very contentious and instead now thought to just be some stem group. For the coloration of these two I decided since they were once thought to be them, as well as living in somewhat analogue habitats to base them off the Marbled Lungfish (Protopterus aethiopicus) and Australian Lungfish (Neoceratodus forsteri)
Top to Bottom: Palaeospondylus gunni, P. australis
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