Amphechinus cf. baudeloti GIBERT , 1974

Bonilla-Salomón, Isaac, Cailleux, Florentin, Joniak, Peter, Ivanov, Martin & Sabol, Martin, 2024, Herpetotheriidae, Talpidae, And Erinaceidae From The Early Miocene Fissures Of Mokrá-Quarry (South Moravia, The Czech Republic), Fossil Imprint 80 (2), pp. 269-284 : 273-274

Amphechinus cf. baudeloti GIBERT, 1974

Text-fig. 4

S t u d i e d m a t e r i a l a n d m e a s u r e m e n t s. MWQ2/2003: one I1 (Pal. 3398: 1.60×1.18); one P2 (Pal. 3544: 1.64×1.13); one left M1 (Pal. 3504: 3.32×3.46×3.65); one fragment of right M1 (Pal. 3505); two left M2 (Pal. 3396: 2.65×3.24×2.40; Pal. 3507: 2.45×3.19×2.43); one right M2 (Pal. 3506: 2.60×3.20×2.46).

MCQ3/2005: one left M2 (Pal. 3932: 2.74×3.37×2.50).

D e s c r i p t i o n. I1. The incisor is large and robust, with a slightly caniniform morphology. The root is curved posteriorly.

P2. The tooth has two roots. The main cusp is placed in an anterolabial position ( Text-fig. 4a). There is a short, central, posterior crest reaching the posterolabial edge of the tooth.

M1. Pal. 3504 is complete ( Text-fig. 4b), whereas in Pal. 3505 only the lingual half of the tooth is preserved ( Text-fig. 4c). The tooth has a quadrangular shape; all the cingulums are well-developed. The protocone is conical; the preprotocrista is thicker than the other crests and ends at the base of the paracone, without fusing with it. The protoconule is not distinguishable. The paracone is somewhat wider than the protocone. There is a small parastyle anterior to the paracone (Pal. 3504; Text-fig. 4b). The postprotocrista joins the prehypocrista and runs towards the metaconule, which is rounder in Pal. 3505 ( Text-fig. 4c). There is a well-marked groove that separates the metaconule from the base of the high metacone. There is a well-developed postmetacrista, but a metastyle is absent. The posthypocrista is weak and short.

M2. These teeth are characterized by a shortening of the postmetacrista and an enlargement of the parastyle compared to M1 ( Text-fig. 4d–g). Both the anterior and posterior cingulum are well-developed. There is a very large parastyle in Pal. 3506, whereas in Pal. 3507 it is much smaller. A low preprotocrista starts from the protocone, joining the base of the high paracone. The postprotocrista leads directly to the metacone. The metaconule is fused into the postprotocrista. There is a short prehypocrista and an incipient posthypocrista. The former ends below the postprotocrista.

R e m a r k s. Erinaceinae remains in the fossil record are usually very rare and fragmented. Their phylogeny is poorly known (Ziegler 2005, Engesser 2009, van Dam et al. 2020, Cailleux et al. 2023). According to van Dam et al. (2020), the scarcity of Erinaceinae remains is due to a combination of their overall rarity in the ecosystems compared to other small mammals and their lesser abundance in the diet of birds of prey ( Corbet 1988).

Only three Erinaceinae genera are recorded from the Early Miocene of Europe. These include the genus Dimylechinus HÜRZELER, 1944 , last recorded in MN 2 ( Hugueney 1997, Hugueney and Maridet 2022), and the advanced genus Mioechinus BUTLER, 1948 , first recorded in MN 4 of Spain ( Crusafont et al. 1955). Many Early Miocene assemblages are attributed to several species of the genus Amphechinus , recorded in Europe from the late Oligocene to the Middle Miocene (e.g., Baudelot 1972, Gibert 1974, Ziegler 1990, 2005, Hugueney and Maridet 2022). The earliest Miocene species of Amphechinus (e.g., A. arvernensis BLAINVILLE, 1839 , A. edwardsi FILHOL, 1879 ) were small, with typically insectivorous antemolars bearing many small sharp cusps and ridges ( van Dam et al. 2020), together with rectangular M1 and uncompressed M2 (see Viret 1938, Ziegler 1998b, Ziegler et al. 2007). These characteristics are not consistent with those found in the assemblage from Mokrá-Quarry.

Amphechinus is not recorded in Europe during the MN 3. The European forms identified in MN 4 sites show cranial and morphological characteristics that reflect a broadening of the dietary spectrum and are characterized by a more squared M1 and a greater posterior reduction of the M2. In the Miocene of Spain, Amphechinus has been recovered from several sites (see van den Hoek Ostende and Furió 2005). Notably, Amphechinus baudeloti from MN 4 assemblages shares morphological similarities with the sample from Mokrá-Quarry, despite its slightly larger size. Moreover, this species often shows a distinct metaconule and a hypocone connected to the postprotocrista, which is indicative of already modern Amphechinus species ( Baudelot 1972, Gibert 1974, van Dam et al. 2020). This is also observed in the M1s from Mokrá-Quarry.

Concerning MN 4 sites from Central Europe, remains of Amphechinus have been identified in the German localities of Petersbuch 2 and Erkertshofen 2 ( Ziegler 2006). However, no descriptions, measurements or figures have been published. Regarding Czech sites, in the preliminary faunal lists of Fejfar and Roček (1988) and Fejfar and Sabol (2005) about Dolnice, no remains of Amphechinus are listed. The same applies to the MN 3 sites of Ahníkov I and Tuchořice, in which the faunal list published by Fejfar et al. (2003), and the later description of Erinaceidae by van den Hoek Ostender and Fejfar (2006) mentions no remains of Amphechinus . Therefore, the case of Mokrá-Quarry constitutes the only Czech site where remains of the genus have been found so far. Based on the evolutionary stage of the morphological characteristics, the Amphechinus from Mokrá-Quarry probably represents an early occurrence of A. baudeloti . However, the scarcity of the recovered remains and the somewhat smaller size prevents a more confident statement about its taxonomical status. Therefore, it is referred to here as Amphechinus cf. baudeloti .