Short one today.
One more fish enters the LRT. Some changes (like a prefrontal) are added to previously nested taxa.
Adding the Carboniferous fish,
Platysomus (Fig. 1) , to the large reptile tree (LRT, 1713+ taxa; Fig. 2) to no one’s surprise nests it with Cheirodus (= Chirodus, Amphicentrum; Fig. 1), a less stretched-out version.
None of these taxa
have a maxilla and they share a long list of other synapomorphic traits.
Platysomus parvulus (Agassiz 1843, Carboniferous to Permian; 18cm long) is a taller, more disc-like fish related to Cheirodus. Note the reduction of the mandible. Considered a plankton eater.
Apologies for the bone ID changes.
I’m learning as I go and revising the naming system so homologies with tetrapods can be more readily understood. Someone had to do it. Why wait until 2021 or thereafter?
Agassiz L 1833, 1837 in Agassiz L 1833-1843. Recherches sur les Poissons fossiles-I, I, III, Neuchatel, pp 1420.