Ammonites angulicostatus, d'Orbigny, 1841

Hoedemaeker, Philip, 2013, Genus Pseudothurmannia Spath, 1923 and related subgenera Crioceratites (Balearites) Sarkar, 1954 and C. (Binelliceras) Sarkar, 1977 (Lower Cretaceous Ammonoidea), Revue de Paléobiologie 32 (1), pp. 1-209 : 6-7

2.3. A. angulicostatus d’Orbigny belongs to genus Crioceratites Léveillé, 1837

The ornamentation of the inner whorls of Ammonites angulicostatus d’Orbigny is totally different from the ornamentation drawn on d’Orbigny’s figure, and from that of all other species currently assigned to Pseudothurmannia , including Lapeyre’s neotype and P. pic- teti Sarkar. The combination of slightly crioconic inner whorls with prominent trituberculate main ribs is unknown in the other species of Pseudothurmannia , but common in Crioceratites . On account of this combination of characteristics, the author is of the opinion that A. angulicostatus d’Orbigny has to be included in the genus Crioceratites Léveillé, 1837 , whereas the other species currently assigned to Pseudothurmannia should be separated from Crioceratites as a separate genus. Here we are dealing with a case of misinterpretation, not misidentifi- cation, of the holotype of A. angulicostatus d’Orbigny. The latter is not congeneric with A. angulicostatus Pictet , non d’Orbigny (= Pseudothurmannia picteti Sarkar, 1955 ), nor with Lapeyre’s neotype of P. angulicostatus d’Orbigny [= Pseudothurmannia ohmi (Winkler, 1868) ], nor with any other species currently assigned to Pseudothurmannia .

A second specimen identical to A. angulicostatus d’Orbigny has not yet been figured in literature. This implies that this species is rare. In 1971 to 1973, the author sampled many specimens currently assigned to Pseudothurmannia from Chamateuil (near Castellane, Alpes-de-Haute-Provence), with the same purpose as Lapeyre, but none of the specimens found could be considered identical to the holotype of d’Orbigny. The specimen chosen by Lapeyre as the neotype of Pseudothurmannia angulicostata (d’Orbigny) can now be identified as Pseudothurmannia ohmi (Winkler, 1868) . Of all species of Pseudothurmannia , the appearance of the latter species approaches most closely to the erroneous drawing of Ammonites angulicostatus in d’Orbigny’s Paléontologie française.

However , in the Tornajo Mountain (municipal district of Lorca, Spain) the author found a second specimen of Crioceratites angulicostatus d’Orbigny , which perfectly exhibits the ornamentation of the inner whorls. It has the same adult ornamentation as the holotype including the faint ventrolateral rows of tubercles, the same measurements and the same subquadratical whorl section, which is diagnostic for the species. The whorls are just not in contact .

2.4. Legitimate type species of Pseudothurmannia Spath, 1923

As to the type species of the genus group Pseudothurmannia there are now two options. The first option is that the newly recovered holotype of the nominal species Ammonites angulicostatus d’Orbigny, 1841 , should remain the type species. This would have been the normal procedure before 2000 and in accordance with the third edition of the International Code of Zoological Nomenclature (1961). After 2000 this option was chosen by Vermeulen (July 2002, 2004), Vermeulen et al. (November 2002), and Busnardo (2003). This option has, however, the disadvantage that genus Pseudothurmannia would then merely embrace the three species of the angulicostata group, which consist of species that are totally different from the group of 16 species that over the past 80 years have been considered to belong to Pseudothurmannia .

To avoid confusion and to maintain stability in nomenclature, it would be better to retain the name Pseudothurmannia for this latter group. This second option is preferred here. Before 2000 this possibility would have only been possible through the intervention of the ICZN (International Commission on Zoological Nomenclature). Sarkar’s (1955) proposal to regard the holotype of Pseudothurmannia picteti Sarkar, 1955 , as type species of Pseudothurmannia was, therefore, in conflict with the code of zoological nomenclature then. However, in the fourth edition of the code (1999), which became effective on 1st January 2000, a new article (article 70.3) was inserted, permitting the author, in the interest of stability in nomenclature, to fix as type species the non-deliberately misidentified nominal species that has previously been fixed as such. This means that Pseudothurmannia picteti Sarkar may now legitimately be considered the type species of Pseudothurmannia without the intervention of the ICZN. This second option has been followed by Company et al. (June 2002, p. 84, 2003) and is endorsed by the author.

There is still a problem, because both options for designating the type species of Pseudothurmannia are simultaneously valid. The International Code of Zoological Nomenclature (1999) failed to state that, if it can be demonstrated that the original type species is misidentified as being conspecific with the nominal species, then article 70.3.2. (misidentified type species) automatically overrules article 70.3.1. (nominal type species). The author holds this view. This omission of the Code would mean that the first author, who designates the type species after the 1st of January 2000 , still has priority. This is illogical and cannot be the purpose of this article. However, in designating the type species of Pseudothurmannia after 2000, Company et al. (June 2002) still have priority over Vermeulen (July 2002) .

In 2009 Vermeulen considered Pseudothurmannia picteti Sarkar, 1955 to be a nomen nudum, because Sarkar did not formally indicate a holotype, did not specify the distinguishing characters and did not give a diagnosis nor a description of the new species. However, every author is entitled to give a described and figured specimen a new name, if he is able to substantiate that the original identification is wrong, and that is what Sarkar did.

Since Company et al. (2002), in accordance with the new article, designated Pseudothurmannia picteti Sarkar as type species of Pseudothurmannia Spath , the species Ammonites angulicostatus d’Orbigny automatically lost its status of type species, and can, without violating the rules, be considered to belong to the species Crioceratites . Pseudothurmannia picteti Sarkar is also the type species of Pieuriceras Vermeulen, 2003, which renders Prieuriceras a junior objective synonym of Pseudothurmannia . However, as the type species of Pseudothurmannia belongs to the group of species with lateral nodes on the main ribs in middle and late ontogenetic stages, this also means that this group has to be regarded as Pseudothurmannia sensu stricto. In this article this group is given the status of subgenus and referred to as Pseudothurmannia (Pseudothurmannia) . This group has been regarded by Wiedmann (1962) and Busnardo (1970, 2003) as not belonging to Pseudothurmannia ; they grouped them into a separate subgenus Crioceratites (Sornayites) Wiedmann, 1962 . Wiedmann (1962, p. 140) stated that the species of this group have trituberculate ribs in all stages of development. Wiedmann chose Emericiceras paronai Sarkar, 1955 , as type species of Sornayites , which is not congeneric with the laterally tuberculated species of P. ( Pseudothurmannia ). Emericiceras paronai is adorned with long ventrolateral spines on the main ribs, which are absent in P. ( Pseudothurmannia ); E. paronai also lacks the ventrolateral rows of small uniform clavi, which characterize P. ( Pseudothurmannia ), and has lateral tubercles on the inner whorls, which, in contrast to the assumption of Wiedmann, are absent in P. ( Pseudothurmannia ). However, Wiedmann did not include Pseudothurmannia picteti Sarkar nor Pseudothurmannia pseudomalbosi Sarasin & Schöndelmayer, 1901 , in Sornayites , because he saw that these species lack lateral tubercles on the inner whorls.

Busnardo (2003) followed Wiedmann (1962) in separating the species with lateral tubercles in the adult as Sornayites from the species without them. However, Busnardo (2003, p. 72) proposed Pseudothurmannia simionescui Sarkar, 1955 , to be the type species of genus Sornayites , because the type of the latter could not be found. This proposal is not in accordance with the International Code of Zoological Nomenclature (1999), because Pseudothurmannia simionescui Sarkar, 1955 , cannot be considered the neotype of Sornayites paronai (Sarkar, 1955) . Thomel (1965b) also separated the species with trituberculate ribs in middle to late ontogenetic stages from the other species of Pseudothurmannia , not as Sornayites , but as Crioceratites , because he rightly regarded Sornayites as a problematic genus.

The above sketched misinterpretations of the type species are merely due to the wrong illustrations of Ammonites angulicostatus by d’Orbigny (1841) and Pictet (1863), for in both figures the lateral tubercles have not been depicted.