An illustration of Xiphactinus labelled as a tarpon, from Schultz (1952).
In an earlier post, I uncovered the origin of the common name “sabre-toothed tiger”. This time I researched a less well-known, but no less interesting, name: “bulldog tarpon”. It refers to the ichthyodectid fish Xiphactinus audax, a famous inhabitant of the Western Interior Seaway. It is an inaccurate moniker because Xiphactinus is neither closely related to nor an ecological analogue for tarpons (Megalops spp.) (Shelburne, 2020). An alternative without those misleading connotations, “X-fish”, was proposed by Alan Detrich in 2000 (Detrich, 2000). The first usage of bulldog tarpon was by C. Bertrand Schultz in 1952 (Schultz, 1952: p. 11).
“Although not strictly a trout, our heroic fish, Portheus molossus, the ‘bulldog tarpon,’ is closely related to the trout, salmon and herring.”
He applied it to Portheus molossus, which is now considered a junior synonym of X. audax. The latter was named by Joseph Leidy in 1870 (Leidy, 1870), while the former was named by Edward Drinker Cope in 1871 (Cope, 1871). The bulldog part comes from the etymology of P. molossus, which was mentioned by Cope in a later paper (Cope, 1872: p. 335).
“The lower jaw was deep, and gave the countenance that bull dog expression from which it derives its name.”
It was likely formed from the Ancient Greek word Molossos, a breed of short-faced dog, which has been featured in other scientific names (e.g., the bats Molossus and Molossops) (Jaeger, 1944). This meaning was translated to the common name “bulldog fish” by William H. Ballou in 1898 (Ballou, 1898).
Artwork of the Western Interior Seaway fauna where Xiphactinus is called a bulldog fish, from Ballou (1898).
The same year, Oliver P. Hay described anatomical similarities between Xiphactinus and tarpons (Hay, 1898), now known to be superficial. It seems that Schultz combined the association with bulldogs established by Cope and Ballou and the connection with tarpons started by Hay. The evolution of bulldog tarpon over 82 years is a strong contrast to sabre-toothed tiger, which only took 3 years. Another notable difference is that bulldog tarpon still denotes the same taxon it was coined for.
References
- Ballou, W.H. (1898, June). The serpentlike sea saurians. Appletons’ Popular Science Monthly, 53, 209-225.
- Cope, E.D. (1871). Sketch of an expedition in the valley of the Smoky Hill River in Kansas. Proceedings of the American Philosophical Society, 12, 174-176.
- Cope, E.D. (1872). On the families of fishes of the Cretaceous formation of Kansas. Proceedings of the American Philosophical Society, 12, 327-357.
- Detrich, A. (2000, November/December). Prehistoric symbol. Kansas Wildlife & Parks, 57(6), 34.
- Hay, O.P. (1898). Observations on the genus of fossil fishes called by Professor Cope, Portheus, by Dr. Leidy, Xiphactinus. Zoölogical Bulletin, 2(1), 25-54.
- Jaeger, E.C. (1944). A source-book of biological names and terms. Charles C. Thomas.
- Leidy, J. (1870). On ichthyodorulites. Proceedings of the Academy of Natural Sciences of Philadelphia, 22, 12-13.
- Schultz, C.B. (1952). Tarpon fishing in Nebraska. Outdoor Nebraska, 30(2), 11.
- Shelburne, E.C. (2020). An assessment of convergence in the feeding morphology of Xiphactinus audax and Megalops atlanticus using landmark-based geometric morphometrics [Master’s thesis, Fort Hays State University]. FHSU Scholars Repository. http://doi.org/10.58809/FBRA1021
Incertae Sedis 