Comment on the proposed conservation of Palamopus E. Hitchcock, 1845 (Ichnotaxa, Reptilia?) (Case 3348)

1. The term ‘Sauroidichnites’ was coined by Edward Hitchcock in 1837 as a subdivision of the general term ‘Ichnites’, and immediately afterwards used as a suborder of the order ‘Dipodichnites’ in the class ‘Ichnolithes’ (Hitchcock, 1841, 1844), thus in the first place ‘Sauroidichnites’ must be regarded as a suprafamilial taxon. Haubold (1971, 1974) pointed out that only in 1845 did Hitchcock begin to use generic names (i.e. different from higher level terms). Indeed, Hitchcock (1848, p. 130) stated that he had introduced the term ‘Sauroidichnites’ intending, by the term, merely to convey an intimation that they might prove to be reptilian. It is therefore argued that ‘Sauroidichnites’ (and likewise ‘Ornithichnites’ and ‘Tetrapodichnites’) was not used as a generic name in the sense of binominal nomenclature, but as a general term denoting an object class, in which case ‘Sauroidichnites’ is unavailable as a generic name and does not need to be suppressed.

2. However, as Hitchcock (1837) subdivided the ‘Ornithichnites’ into ‘Pachydactili’ and ‘Leptodactyli’ and used ‘Ornithichnites’ to include several inchnospecies, it could be argued that Sauroidichnites, Ornithichnites and Tetrapodichnites were used as generic appellations and general terms at the same time and could be acceptable as available generic names, possibly in the sense of a ‘collective group’.

3. The question of the type species can be summarized as follows: Hitchcock (1837) used Sauroidichnites to include five species-group names. The type ichnospecies of the ichnogenus Sauroidichnites Hitchcock, 1837 – if considered available – is Sauroidichnites palmatus (Hitchcock, 1836) by original monotypy, as the four other species names coined by Hitchcock in 1837 without description are unavailable. However, although it is the older name and an objective synonym, Palamopus palmatus is not the type species of Palamopus, as implied by Rainforth (para. 2). The type species (by monotypy) is Palamopus anomalus Hitchcock, 1845, as correctly stated by Hay (1902). If Sauroidichnites and Ornithichnites are considered unavailable generic names, that does not affect the availability of ‘Ornithichnites’ palmatus, the valid specific name of the type species of Palamopus (Article 11.9.3.1 of the Code). Should the name palmatus prove to be nomenclaturally unavailable, P. anomalus may be reinstated as the valid name of the type species.

4. Rainforth stated that Palamopus has been used as the name for an ichnotaxon in four published works (Kuhn, 1963; Haubold, 1971, 1984; Olsen & Radian, 1986). Kuhn (1963) accepted only Palamopus Hitchcock, 1845 with P. palmatus (Hitchcock, 1841, note date, with Sauroidichnites palmatus in synonymy) as the valid name of the type species (‘Genotypus’), thus apparently ignoring the older references. However, Kuhn (1963) cited the works of Hitchcock older than 1841, and there is no doubt that Kuhn had actually seen them, as the first series of volumes of the American Journal of Science and Arts is available, with early 19th century possession stamps, in the Bayerische Staatsbibliothek in Munich, which was Kuhn’s main literature source (Kuhn, 1963, p. 3). It is therefore concluded that Kuhn, possibly following Hay (1902) and others, consistently did not accept species names in these older works as available, and generic names only beginning with Hitchcock, 1845. Haubold (1971 and follow-up publications of 1974 and 1984 in the second, enlarged edition) explicitly considered Sauroidichnites as not available as a generic name, following Kuhn (1963, and the references cited therein); hence, he used Palamopus (Haubold, 1971), with Sauroidichnites in synonymy. Finally, Olsen & Padian (1986, p. 261) listed Palamopus only in the synonymy of Batrachopus, and more specifically three species of Palamopus, including ‘P. palmatus Hitchcock, 1841’, in tentative subjective synonymy with Batrchopus deweyi (Hitchcock, 1843) (Olsen & Padian, 1986, p. 262), so this reference cannot be counted as usage of Palamopus as the valid name of a taxon.

5. To summarize: Of the limited record of only four works cited by Rainforth to support a universal usage of the younger name Palamopus, instead of the older Sauroidichnites during the past 50 years, one work did not use Palamopus as a valid name, two used Palamopus with Sauroidichnites in explicit synonymy, and three did not consider Sauroidichnites an available generic name in zoological nomenclature. An accurate record by Lockley & Meyer (2004, p. 174) for Palamopus as a (presumably) valid taxon name was published probably too late to be employed by Rainforth. However, four references, at the most, cannot be considered as establishing prevailing usage. The nomenclature would hardly be upset, if the older name Sauroidichnites was be used and strict priority would be reinstated. It is my
contention, therefore, that the proposed suppression of Sauroidichnites is not supported by the reasoning of Rainforth. However, I strongly recommend following previous authors in considering Sauroidichnites Hitchcock, 1837 as not available as a generic name for reasons stated in para. 1 above.

6. Therefore, amending the application by Rainforth, the International Commission on Zoological Nomenclature is accordingly asked:
(1) to place on the Official List of Generic Names in Zoology the name Palamopus E. Hitchcock, 1845 (gender: masculine), type species by monotypy Palamopus anomalus E. Hitchcock, 1845;
(2) to place on the Official List of Specific Names in Zoology the name palmatus E. Hitchcock, 1836, as published in the binomen Ornithichnites palmatus (senior objective synonym of the type ichnospecies of Palamopus E. Hitchcock, 1845);
(3) to place on the Official Index of Rejected and Invalid Generic Names in Zoology the name Palamopus E. Hitchcock, 1848 (a junior synonym of Palamopus E. Hitchcock, 1845);
(4) to place on the Official Index of Rejected and Invalid Specific Names in Zoology the name anomalus E. Hitchcock, 1845, as published in the binomen
Palmopus anomalus (junior objective synonym of Ornithichnites palmatus E.
Hichcock, 1836).

Additional references

Haubold, H. 1974. Die fossilen Saurierfährten. 168 pp. Ziemsen Verlag, Wittenberg Lutherstadt.
Lockley, M.C. & Meyer, C. 2004. Crocodylomorph trackways from the Jurassic to Early Cretaceous of North America and Europe: implications for ichnotaxonomy. Ichnos, 11(1–2): 167–178.