Updated January 16, 2021
with revised scores that now nest Xiphias, the swordfish, between Bavarichthys and Anguilla, the European eel. This is a novel hypothesis of interrelationships supported by skull shape and details, lack of ribs (in eels and swordfish) and a lack of pelvic fins in these two taxa. Traditionally these three taxa nest with other taxa. This clade is close to the anchovy clade in the LRT.
Today the extant topminnow,
Fundulus (Figs. 1), nests in ‘the Right Side’ of the Osteichyes, the clade that includes only ray fins (Fig. 2). The more taxa, the better cladodgram. Earlier errors are here corrected by the addition of taxa and data, some of which provide views not available earlier. Such work is still rewarding.
Adding characters would never have resolved this issue.
Only adding taxa can do so, contra what so many PhDs say. Not sure why. It didn’t make sense in 2012 and it still doesn’t make sense in 2020. More characters are not needed. More taxa smooth out all the rough edges, illustrating the microevolution that ultimately creates macroevolution.
An overlooked European eel ancestor,
Bavarichthys (Arratia and Tischliner 2010; Late Jurassic) is here identified.
(Arratia and Tischlinger 2020; Late Jurassic) was originally considered a member of the “Crossognathiforms with a large head about 30% in standard length and a characteristically elongate snout, more than 25% in head length.“ In the LRT it nests between the extant anchovy, Elops and the extant European eel, Anguilla.
(Johnson et al. 2011; 18cm; Fig. 7) is a newly discovered ‘living fossil” transitional taxon from Bavarichthys to Anguilla. Distinct from eels, Protanguilla has gill rakers, fewer than 90 vertebrae, pterotic does not approach anterior margin of pterosphenoid, and the latter bone participates in the posterior margin of the orbit. Eels are traditionally associate with Elops. These new taxa fill in the gaps.
The nesting of Bavarichthys
basal to Protanguilla and Anguilla appears to be a novel hypothesis of interrelationships. Let me know if there is an earlier citation so I can promote it.
Arratia G and Tischlinger H 2010. The first record of Late Jurassic crossognathiform fishes from Europe and their phylogenetic importance for teleostean phylogeny. Fossil Record 13(2):317-341.
Johnson GD, Ida H, Sakaue J, Sado T, Asahida T and Miya M 2012. A ‘living fossil’ eel (Anguilliformes: Protanguillidae, fam nov) from an undersea cave in Palau. Proceedings of the Royal Society. (in press): 934–943. doi:10.1098/rspb.2011.1289