Galliconularia, Van Iten & Lefebvre, 2020

Iten, Heyo Van & Lefebvre, Bertrand, 2020, Conulariids from the Lower Ordovician of the southern Montagne Noire, France, Acta Palaeontologica Polonica 65 (3), pp. 629-639 : 632

Genus Galliconularia nov.

Zoobank LSID: urn:lsid:zoobank.org:act:F7CBF965-787C-4414-89A3-8CFE1F228C63

Type species: Conularia azaisi Thoral, 1935 , by monotypy see below. Etymology: From the Latin gallicus, meaning of or pertaining to Gaul or France, and Conularia .

Diagnosis.—As for the type species by monotypy.

Remarks.— Galliconularia is a highly distinctive genus, the most conspicuous characteristic of which is the presence of a broadly elevated facial midline together with very fine, trochoidal transverse ribs which are continuous across this feature. Additional notable features of the new genus are the presence on or within the faces of accessory longitudinal furrows or ridges (“filets”; Thoral 1935: 160) and (at least in some specimens) minute nodes and interspace ridges. Only three previously described genera, Climacoconus Sinclair, 1942 , Pseudoconularia Bouček, 1928 , and Reticulaconularia Babcock and Feldmann, 1986 , share with Galliconularia the presence of an external midline ridge (see e.g., Van Iten et al. 2000, 2020). Unlike Galliconularia , however, Pseudoconularia lacks transverse ribs and its nodes are elongate and coarse, and the transverse ribs of Climacoconus and Reticulaconularia are coarse and usually alternate along the facial midline (see e.g., Sinclair 1942: pl. 3: 7). Moreover, no other genus or species exhibits trochoidal transverse ribs as fine as those of Galliconularia , though the pattern of arrangement of its tiny nodes and interspace ridges is similar to that of certain species in Conularia and Paraconularia . Superficially, specimens of G. azaisi exhibiting narrow longitudinal ridges or furrows coupled with adapical recurvature (scalloping) of the transverse ribs (Fig. 4E) resemble the faces of Glyptoconularia Sinclair, 1952 , which bears a distinctive ornament consisting of longitudinal files of short, straight, or adaperturally arching transverse ridges collectively resembling chain mail ( Van Iten 1994). The fine longitudinal ridges are also similar to the “accessory longitudinal lines” ( Sinclair 1952: 139) commonly seen in specimens in the genus Archaeoconularia . Owing in part to deformation of available specimens of Galliconularia , it is difficult to discern details of the anatomy of the corner sulcus. Nevertheless, it appears that like Conularina Sinclair, 1942 , Eoconularia , and Glyptoconularia , Galliconularia exhibits termination or severe diminution of the transverse facial ornament in or near the corner sulcus. Importantly, Van Iten et al. (2016b: 1) interpreted this similarity as a non-homoplasic synapomorphy uniting these four taxa in a single, monophyletic group that excludes other conulariids. G. azaisi (shown in the cladogram of Van Iten et al. 2016b as “ Eoconularia ” azaisi ) is the basalmost taxon of this fully resolved clade. According to the phylogenetic analysis of Van Iten et al. (2016b), the midline ridge was derived independently in Galliconularia (coded as Conularia azaisi ), Pseudoconularia , and the minor clade consisting of Climacoconus and Reticulaconularia . Trochoidal transverse ribs, a primitive feature present in Galliconularia , Conulariella , and many other conulariids, were lost in at least two lineages, including the lineage leading to the most recent common ancestor of Conularina and Eoconularia . However, Van Iten et al. (2016b) also scored G. azaisi as lacking nodes and interspace ridges, features which were detected in two specimens assigned to this species in the present study. Therefore, the phylogenetic relationships of G. azaisi to other conulariids should be reanalyzed based on the new anatomical data revealed by the present study.