Cheirolepis holotype, Bonnerichthys and Bluefieldius

Bluefiedius mercerensis (Mickle 2018, Late Mississippian, KUVP 155843) was originally described without a phylogenetic analysis. Here this little fish nests with the large spiny sharks, the Cheirolepis holotype and Bonnerichthys. Note the downturned premaxilla.

Cheirolepis (holotype, Agassiz 1835; Pearson and Westoll 1979; Early to Middle Devonian, up to 55cm) nests as a spiny shark in the LRT. Fewer teeth line the deeper jaws of this relatively large suspension feeder with descendants like Bonnerichthys.. The tail is strongly heterocercal. Slender pines support the lateral fins.

The skull is reconstructed here different than the classic drawing from a century ago (lowest image). Perhaphs two unrelated specimens were used to create a chimaera.

Bonnerichthys gladius (Friedman et al. 2010; originally Portheus gladius, then Protosphyraena gladius (Cope 1873) est. 4-5m long; Late Cretaceous) was considered a giant, toothless, Niobrara plankton eater related to Pachycormus. Here it nests with the holotype specimen of Cheirolepis (above).

Shown here is the original reconstruction (ghosted) and a DGS reconstruction (color) based on bones in Friedman et al.).

Sinacanthus wuchangensis (P'an 1959, Zhu 1998; Early Silurian) had fins spines similar to those found in Late Cretaceous Bonnerichthys.

Agassiz JLR 1835. Recherches sur les Poissons fossiles, 5 volumes. Imprimerie de Petitpierre et Prince, Neuchaatel, 1420 pp.

Burrow CJ 2011. A partial articulated acanthodian from the Silurian of New Brunswick, Canada. Canadian Journal of Earth Sciences. 48 (9): 1329–1341.

Burrow CJ and Rudkin D 2014. Oldest Near-Complete Acanthodian: The First Vertebrate from the Silurian Bertie Formation Konservat-Lagerstätte, Ontario. PLoS ONE 9(8): e104171. https://doi.org/10.1371/journal.pone.0104171

Deecke W 1889. Über Fische aus verschiedenen Florozonten der Trns. Palaeontographicd, 35: 97-L38, pls. 6-8, Stuttgart.

Deecke W 1911. Neueus Jahrbuch fur Minerologie 1911 (2):70.

Friedman M, Shimada K, Martin LD, Everhart MJ, Liston JJ, Maltese A and Triebold M 2010. 100-million-year dynasty of giant planktivorous bony fishes in the Mesozoic seas. Science 327(5968):990-993.

Friedman M 2011, 2012. Parallel evolutionary trajectories underlie the origin of giant suspension-feeding whales and bony fishes. Proceedings of the Royal Society B 279, 944–951. doi:10.1098/rspb.2011.1381

Long JA 1995. The Rise of Fishes. Johns Hopkins University Press. Baltimore and London.

Mickle KE 2018.A new lower actinopterygian fish from the Upper Mississippian Bluefield Formation of West Virginia, USA. PeerJ 6:e5533; DOI 10.7717/peerj.5533

Pearson DM and Westoll TS 1979. The Devonian actinopterygian Cheirolepis Agassiz. Earth and Environmwiki/Cheirolepisental Science Transactions of The Royal Society of Edinburgh. 70(13-14):337–399.

Pompeckj JF 1914. Die Bedeutung des Schwäbischen Jura für die Erdgeschichte. Stuttgart, 1914

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