Is Cladodus part of Cladoselachiformes or Ctenacanthiformes

[Joseph Fossil]

As I was recently doing some research on the prehistoric shark genus Cladodus, I came across some info that classifies the genus as a member of the family Cladoselachidae, Order Cladoselachiformes.

 

https://en.wikipedia.org/wiki/Cladoselachidae

 

This is somewhat confusing to me as mindat and the Paleontological Database aka fossilworks list Cladodus as a member of the family Ctenacanthidae, Order Ctenacanthiformes.

 

https://www.mindat.org/taxon-8657177.html

 

http://www.fossilworks.org/cgi-bin/bridge.pl?a=taxonInfo&taxon_no=104838

 

 

I'm personally leaning more towards Cladodus being a member of at least the Ctenacanthiformes. But I'm curious what are the origins of this taxonomic confusion on the genus Cladodus's phylogenetic placement in the Chondricthyan family? Is Cladodus a member of the Cladoselachiformes or Ctenacanthiformes? 

 

What do you guys think?

[PFOOLEY]

Comments on the selachian genus Cladodus Agassiz, 1843

 

Class CHONDRICHTHYES

 

Order CTENACANTHIFORMES Glikman, 1964

Remarks—The ctenacanthiform sharks have two ornamented

dorsal fin spines (see Maisey, 1981) and cladodont teeth with at

least slightly marked basolabial depression, flattened labial face

of the median cusp (Williams, 2001), and bases of all cusps con-

nected by a layer of enameloid and pallial dentine. All neuro-

crania known thus far from the representatives of this order, such

as Ctenacanthus from the Cleveland Shale (CMNH 9456),

Tamiobatis (Eastman, 1897, Williams 1998), and Cladodoides

(Maisey, 2001, 2005) show similar, primitive features, such as the

long otico-occipital region and the wide axial part.

 

Family CTENACANTHIDAE Dean, 1909

Included Genera of Which Teeth are Known—Ctenacanthus

Agassiz, 1837, Cladodus Agassiz, 1843, Tamiobatis Eastman,

1897, Saivodus gen. nov.

 

Genus CLADODUS Agassiz, 1843

[DPS Ammonite]

Look at the references that Wikipedia cited. Pay attention to good recent references to see where the consensus is headed as to the family/order of Cladodus.
https://en.m.wikipedia.org/wiki/Cladodus

 

Realize that taxonomic classifications are opinions. Some agree and some are unsettled. Generally PBDB and GBIF are more reliable than Wikipedia. Pay more weight to recent publications that state opinions with evidence.

 

I just added the PBDB link to Mindat. Both PBDB and GBIF say that Clododus is in family Ctenacanthidae, Order Ctenacanthiformes per more recent articles stated with evidence; go with that. I suspect Duffin and Ginter 2006 can explain why in English since Goto and Okura 2004 is in Japanese.

 

http://www.fossilworks.org/cgi-bin/bridge.pl?a=referenceInfo&reference_no=30312

 

 

https://www.mindat.org/taxon-8657177.html

 

 

 

 

Edited January 18, 2023 by DPS Ammonite