Libys callolepis Ferrante & Menkveld-Gfeller & Cavin 2022, sp. nov.
Creators: name: Ferrante, Christophe
name: Menkveld-Gfeller, Ursula
name: Cavin, Lionel
Publisher: name: Zenodo
Year: 2022
Subjects: Biodiversity
Taxonomy
Animalia
Chordata
Coelacanthi
Coelacanthiformes
Mawsoniidae
Libys
Libys callolepis

description: L. callolepis sp. nov.
Diagnosis
Libys species with the postparietal shield about half the length of the parietonasal shield (the parietonasal is then proportionally shorter than in the type species). Te teeth covering the prearticular are very small, and rounded and smooth. Between 41–47 neural arches. Fin rays are slender than in the type species and then not expanded. Te scales are strongly ornamented with irregularly sized and elongated round-to-ovoid ridges disposed along a longitudinal axis.
Measurements and meristic
(TB) Total body length 290 mm (estimation); (SL) standard length 255 mm.
d1.f= 10; d2.f =16; pect.f =18–22; pelv.f ≥17; ana.f= 20–23; cau.f= 15/14–16; n.a =44–47; h.a= 18–20.
Etymology
From the ancient Greek ΚΑλός, kalós, (‘beautiful’, ‘nice’) and λεπίς, lepís, (‘scale’) in reference to the nicely ornamented scales of the species, which differentiates it from the type species.
Holotype and only known specimen
NMBE 5034072 and 5034073, a sub-complete specimen preserved in right lateral view as part and counterpart. Most of the bones, including the scales on the body, are preserved in anatomical position and only the bones of the cheek and the jaw are missing. Te specimen is kept in the collections of the Natural History Museum Bern (Canton of Bern, Switzerland).
Horizon and type locality
Toarcian (Lower Jurassic), Creux de l’Ours section, locality of Les Pueys near the Teysachaux summit (Canton of Fribourg, Switzerland).
Nomenclatural act
Te present work and its nomenclatural act are registered in ZooBank, the online registration system for the International Commission on Zoological Nomenclature. Te Life Science Identifiers for this publication is “ urn:lsid:zoobank.org:pub: D03A2AC9-51F9-45E6- 8CAC-F06A1526AF2C ” and can be resolved appending the prefix “http://zoobank.org/” in any standard web browser.
Description
Generalities
Most of the bones of the specimen are preserved on the part (NMBE 5034073) (Fig. 3). From the head, most of the dermal bones of the skull roof are preserved. Te bones of the cheek and the lower jaw are missing, revealing then the bones of the palatoquadrate and of the branchial apparatus. Te axial skeleton, the girdles and the fins are almost entirely preserved, except the posterior tip of the supplementary caudal fin lobe. Te scales are well preserved on the entire body in natural position, especially on the counterpart (NMBE 5034072) (Fig. 4).
Te specimen may represent an adult individual as all the basal plates are fully ossified, which is a feature observed in adult coelacanths (e.g., Schultze, 1980; Witzmann et al., 2010). Tis view is reinforced because the specimen shows some well ossified axial mesomere and the scapulocoracoid (Fig. 4A 1, A 5, A 6, B). Although a long supplementary lobe of the caudal fin is considered as a juvenile character (e.g., Forey, 1981; Schultze, 1972), the prominent supplementary lobe of the caudal fin (Fig. 3) observed in the specimen of Teysachaux represents rather a generic character of the specimen.
Dermal bones of the skull roof
Te bones of the skull are only preserved on the part (Figs. 3 and 5). Te skull roof is divided into a parietonasal and postparietal shields, free from one to the other and separated by the intracranial joint, which appears to be straight. Te postparietal shield appears to be smaller than the parietonasal shield, this last being about 1.45 longer. Although slightly lower, this ratio is however close to the ratios of Jurassic and Cretaceous coelacanths that have typically a parietonasal shield circa 1.5 to 2 times longer than the postparietal shield (e.g., Libys polypterus has a ratio of about 1.7). On the Teysachaux specimen, the dermal bones of the skull appear to be smooth and unornamented.
description: Published as part of Ferrante, Christophe, Menkveld-Gfeller, Ursula & Cavin, Lionel, 2022, The first Jurassic coelacanth from Switzerland, pp. 1-20 in Swiss Journal of Palaeontology (15) (15) 141 (1) on pages 5-6, DOI: 10.1186/s13358-022-00257-z, http://zenodo.org/record/11998918