Eumyarion weinfurteri ( Schaub & Zapfe, 1953 )
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publication ID |
https://doi.org/10.3897/fr.28.138478 |
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publication LSID |
lsid:zoobank.org:pub:77E5A585-2B07-4C99-B040-A13033118496 |
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DOI |
https://doi.org/10.5281/zenodo.15643347 |
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persistent identifier |
https://treatment.plazi.org/id/604F7AFC-F928-52BB-85D8-BE950A8B8191 |
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treatment provided by |
by Pensoft |
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scientific name |
Eumyarion weinfurteri ( Schaub & Zapfe, 1953 ) |
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Eumyarion weinfurteri ( Schaub & Zapfe, 1953)
Figs 8 A – T View Figure 8 , 9 View Figure 9
Localities.
FS 1, MAB 3, and MAB 5.
Material (number of remains).
Suppl. material 1; FS 1 (1): 1 m 2; MAB 3 (21): 3 M 1, 1 M 2, 3 M 3, 3 m 1, 6 m 2, 5 m 3; MAB 5 (8): 1 M 1, 1 M 3, 2 m 1, 2 m 2, 2 m 3.
Measurements.
Suppl. material 2.
Description.
m 1 ( MAB 3; Fig. 8 A, B View Figure 8 ): the anteroconid is simple. The anterolophulid may be complete (1 out of 3), low (1 out of 3), or incomplete (1 out of 3). In the latter case, the anterolophulid is a ridge that starts from the protoconid. A ridge begins from the metaconid and may contact the anteroconid (2 out of 3) or not (1 out of 3). The anterior metalophulid is directed slightly forward, and it may either connect with the anterolophulid (2 out of 3) or not (1 out of 3). The posterior metalophulid may contact with the posterior ridge of the protoconid (1 out of 3), there is only a spur (1 out of 3), or absent (1 out of 3). The protosinusid is almost closed by a low ridge coming from the anteroconid. The anterosinusid may be well developed (1 out of 3) or practically disappear by the anterior spur of the metaconid (2 out of 3). The posterior ridge of the protoconid may be short, and does not connect with the mesolophid (1 out of 3) or is of medium size and contacts the mesolophid (2 out of 3). The mesolophid is of medium length. The ectomesolophid may reach the labial margin (2 out of 3) or be absent (1 out of 3). The hypolophulid is transverse and connects with the ectolophid. The posterior ridge of the hypoconid may be present (2 out of 3) or not (1 out of 3), resulting in a high posterolophid connected to the entoconid, which encloses the posterosinusid.
Variability in other sites: in MAB 5 (Fig. 8 C, D View Figure 8 ), the anterior ridge of the metaconid does not contact the anteroconid, the anterior metalophulid is a spur, while the posterior one is directed towards the mesolophid in one specimen. In one, the mesolophid is long, while the ectomesolophid is either a spur or absent. The m 1 from MAB 5 is comparatively larger than that of MAB 3 (Fig. 9 A View Figure 9 ).
m 2 ( MAB 3; Fig. 8 F, G View Figure 8 ): the lingual anterolophid is of medium length, and it may not reach the lingual margin (4 out of 5) or be absent (1 out of 5). The anterosinusid is closed by the anterolophid (4 out of 5) or absent (1 out of 5). The labial anterolophid connects to the base of the protoconid. The metalophulid is simple and connects to the anterolophid. On the lingual side, the posterior ridge of the metaconid connects with the lingual part of the posterior ridge of the protoconid (4 out of 5), or not (1 out of 5), almost completely enclosing the mesosinusid. The posterior ridge of the protoconid is of medium length, and two specimens contact the mesolophid. The mesolophid is medium length (1 out of 6), short (4 out of 6), or absent (1 out of 6). The ectomesolophid may be short (1 out of 5), medium (1 out of 5), or absent (3 out of 5). The posterior crest of the hypoconid is long (2 out of 6) or only a spur (4 out of 6). The posterolophid is high and connects with the entoconid, enclosing the posterosinusid (4 out of 6) or not contacting the entoconid (2 out of 6).
Variability at other sites: FS 1 (Fig. 8 E View Figure 8 ) exhibits no notable differences. However, in MAB 5, the lingual anterolophid is shorter (Fig. 8 H, I View Figure 8 ). Additionally, the m 2 of the study material appears to lengthen with time in terms of biometry (Fig. 9 B View Figure 9 ).
m 3 ( MAB 3; Fig. 8 J, K View Figure 8 ): the lingual anterolophid is short, and the labial one connects with the base of the protoconid. The metalophulid contacts obliquely forward. On the lingual side, the posterior ridge of the metaconid connects with the anterior ridge of the protoconid and with the entoconid, enclosing the mesosinusid. The posterior ridge of the protoconid is of medium-long length. The ectomesolophid may be short (1 out of 5) or absent (4 out of 5). The hypolophulid is transverse and complete. The posterolophid is high and connects with the entoconid, enclosing the posterosinusid.
Variability in other sites: in MAB 5 (Fig. 8 L, M View Figure 8 ), the posterior ridge of the protoconid is more delayed. However, no difference in size is apparent (Fig. 9 C View Figure 9 ).
M 1 ( MAB 3; Fig. 8 N, O View Figure 8 ): The tooth surface is rough. The anterocone is simple and extends transversely. One specimen has an anterior ridge on the labial side of the anterocone. The postero-labial ridge of the anterocone is attached to the labial side of the tooth in one individual, and in another it is isolated. The anterocone has a central posterior ridge: in one specimen it is directed towards the labial side, in another towards the protocone, and in the last one it is straight. The anteroloph may be present (2 out of 3) or absent (1 out of 3). The labial ridge of the anterolophule may be incipient (1 out of 3) or absent (2 out of 3). The anterior ridge of the protocone is directed forward and, in one specimen, connects with the median ridge of the anterocone. The posterior protoloph is transverse and connects labially to the entoloph, posterior to the protocone. The ectoloph may be present (2 out of 3) or absent (1 out of 3). In one individual, there is a double mesoloph. In the latter case, the anterior mesoloph is incipient and is directed towards the posterior mesoloph. The posterior or main mesoloph is long. The ectomesoloph may be absent (2 out of 3) or only a spur (1 out of 3). The sinus is relatively narrow and directed forward. The metaloph is connected to the entoloph. The posteroloph is long, and it may connect to the base of the metacone (1 out of 3) or not (2 out of 3).
Variability is present in other sites: in MAB 5 (Fig. 8 P View Figure 8 ), the absence of a posterior ridge of the anterocone is observed, and the metaloph is connected to the anterior part of the hypocone. No significant disparities in size are detected (Fig. 9 D View Figure 9 ).
M 2 ( MAB 3; Fig. 8 Q View Figure 8 ): The surface is rough. The lingual anteroloph is short. The protoloph is transverse and connects with the protocone. The mesoloph is of medium length. The ectomesoloph is absent. The sinus is narrow and directed forward. The metaloph is transverse and connects with the hypocone. The posteroloph is long and isolated labially.
M 3 ( MAB 3; Fig. 8 R – T View Figure 8 ): the labial anteroloph is characterised as either long (2 out of 3) or medium (1 out of 3) in length, with the possibility of either connecting to the protocone (1 out of 3) or the protoloph (2 out of 3). The lingual anteroloph is either small (2 out of 3) or absent (1 out of 3). The protoloph is simple, transverse, or shifted slightly forward, connecting to the anterior part of the protocone. The posterior ridge of the paracone connects to the base of the metacone, forming a labial cingulum that closes the mesosinus. The neo-entoloph may be complete and high (1 out of 3), short and weak (1 out of 3), or incomplete (1 out of 3). The axioloph may be complete and located in the central part of the tooth (2 out of 3), or long and incomplete (1 out of 3). The mesoloph may be medium (1 out of 3) or long and connects to the labial cingulum (2 out of 3). The metaloph is long and directed forward. The metaloph may connect to the metacone and the neo-entoloph through the axioloph (1 out of 3), the metacone and the posterior part of the protocone (1 out of 3), or the anterior part of the hypocone (1 out of 3). The hypocone may be well developed (1 out of 3) or absent (2 out of 3). The posteroloph may be high and short, connecting the neo-entoloph and the metacone, enclosing a small posterosinus (1 out of 3), which is small and isolated (1 out of 3), or high, short, and not connected to the metacone (1 out of 3).
Variability is present in other sites: the tooth from MAB 5 is similar to the one described before.
Remarks.
The genus Eumyarion is a small to medium-sized muroid characterized by primitive dental features ( Thaler 1966). The origins of this genus are complex and likely related to Eucricetodon from the Oligocene and Early Miocene ( Kälin 1999). A comprehensive revision of both genera could potentially result in their synonymy, encompassing some basal forms of Eumyarion ( Kälin 1999; de Bruijn et al. 2013).
The provenance of this genus has been the subject of considerable debate among scholars, with various authors proposing a range of potential locations. These include the upper Oligocene in Turkey ( Ünay et al. 2003), the MN 1 in Asia ( Lopatin 2004 a; Maridet et al. 2011), and the upper Oligocene in Europe, more specifically in Bosnia and Herzegovina, have all been proposed as potential locations for the origin of this genus. ( de Bruijn et al. 2013). The earliest known fossil of this species from Central and Western Europe was discovered at Dolnice 1 in the Cheb Basin in the Czech Republic and dates back to the first half of the lower Aragonian ( MN 4; Fejfar 1989). During the Early-Middle Miocene in Europe, a variety of species of Eumyarion were present, namely Eumyarion bifidus ( Fahlbusch, 1964) , Eumyarion latior ( Schaub & Zapfe, 1953) , Eumyarion medius ( Lartet, 1851) , and E. weinfurteri (which may be a synonym of E. latior , according to de Bruijn (2009)). In addition, within the geographical confines of Turkey, the following species have been identified: Eumyarion carbonicus de Bruijn & Saraç, 1991 , Eumyarion orhani de Bruijn et al., 2006 , Eumyarion montanus de Bruijn & Saraç, 1991 , Eumyarion beyderensis Bilgin et al., 2023 , Eumyarion aegeaniensis Bilgin et al., 2023 , and Eumyarion gordesensis Peláez-Campomanes et al., 2019 were also discovered ( de Bruijn 2009; Peláez-Campomanes et al. 2019; Bilgin et al. 2023).
In the Iberian Peninsula, the earliest fossil records date from the lower Aragonian (upper part of the MN 4), specifically at the localities of Buñol (Cerro de la Cruz, Magro River Basin, last part of the local biozone C; Daams and Freudenthal (1974); local biozone according to Crespo et al. 2019), Montalvos 2 (Teruel Basin, local biozone Ca, Hordijk et al. 2015), Vargas 4 A (Calatayud-Montalbán Basin, local biozone Cb, van der Meulen et al. 2012), and Les Cases de la Valenciana, Can Martí Vell, Els Casots or San Mamet (Vallès-Penedès Basin, local biozone C, Casanovas-Vilar et al. 2016, Jovells-Vaquè et al. 2017). During the Early Miocene appear in the Iberian Peninsula, the species E. medius , Eumyarion valencianum Daams & Freudenthal, 1974 (nomem dubium in de Bruijn and Saraç (1991), probably E. weinfurteri or E. latior according to de Bruijn 2009) and E. weinfurteri ( Daams and Freudenthal 1974; Ruiz-Sánchez et al. 2003; Casanovas-Vilar et al. 2016), and subsequently, Eumyarion leemani ( Hartenberger, 1965) ( Hartenberger 1965; Casanovas-Vilar 2007).
The classification of medium-sized Eumyarion poses a considerable challenge, primarily due to the extensive intraspecific variation observed in their morphology and size. This observation has prompted several researchers to synonymise species and question the homogeneity of populations ( Engesser 1972; Vasileiadou and Zouros 2012). A particularly illustrative example of this phenomenon is E. weinfurteri , a species initially synonymised with E. latior by de Bruijn and Saraç (1991), and subsequently by Schötz (1993). However, de Bruijn (2009) subsequently raised questions regarding its status, albeit identifying differences between the two in M 1 and M 2 of Sandelzhausen.
The material of the genus Eumyarion recovered from the Ribesalbes-Alcora Basin exhibits a larger size compared to the smaller species of the genus (namely Eumyarion intercentralis de Bruijn & Saraç, 1991 , Eumyarion microps de Bruijn & Saraç, 1991 ), E. gordensensis , and E. orhani . It is slightly larger than the type population of E. weinfurteri (although resembling other populations of this species), E. bifidus , and E. carbonicus , and exhibits similarities with E. aegeaniensis , E. beyderensis , E. montanus , and E. medius . However, in comparison to E. latior , it is similar or slightly smaller, depending on the specific element (Fig. 9 View Figure 9 ).
The MAB 3 sample exhibits a combination of primitive and derived features in the m 1 morphology, with one specimen displaying an anteroconid that is strikingly similar to that of E. orhani or Eumyarion tremulus Lopatin, 1996 , and lacking protoconid-anteroconid contact. In the remaining material, the anteroconid has a decreasing crescent shape and it is connected to the metaconid and protoconid by a well-developed anterolophulid, a feature typical of E. carbonicus or E. latior / weinfurteri ( Daams and Freudenthal 1974; Bulot 1979; de Bruijn et al. 2006). It differs from E. beyderensis because in this species the anteroconid is near to be isolated, and E. aegeaniensis by this more developed anteroconid ( Bilgin et al. 2023). One specimen displays the distinctive characteristics of E. montanus from Keseköy, i. e., a short mesolophid and a posterior ridge of the protoconid ( de Bruijn and Saraç 1991). Conversely, the remaining specimens exhibit a convergence of both ridges, a morphology consistent with that of E. latior / weinfurteri as observed in Buñol, Aliveri, and Dolnice ( Daams and Freudenthal 1974; Hofmeijer and de Bruijn 1988; Fejfar 1989), or E. orhani ( de Bruijn et al. 2006) . The occurrence of the posterior crest of the hypoconid varies significantly within the genus Eumyarion . It is present in our material in a comparable percentage to E. montanus , E. tremulus , or E. latior / weinfurteri ( de Bruijn and Saraç 1991; Lopatin 2004 a; de Bruijn 2009). The morphological similarity of the m 1 of MAB 5 to the E. latior / weinfurteri populations from Buñol or Aliveri ( Daams and Freudenthal 1974; Hofmeijer and de Bruijn 1988) is remarkable. This element is biometrically smaller than the type population of E. latior , and only MAB 5 is larger than the type population of E. weinfurteri , while the remains of MAB 3 are smaller than the type population of E. medius (Fig. 9 A View Figure 9 ).
The morphology of m 2 is distinctive. In 33 % of the specimens, the posterior ridge of the protoconid is present, a feature that is more commonly seen in more recent species. Conversely, the short or absent mesolophid is a characteristic of more primitive species. This combination of morphologies is a characteristic of E. latior / weinfurteri from Aliveri and Eumyarion margueritae from de Bruijn et al. 2013, from Banovići ( Hofmeijer and de Bruijn 1988; de Bruijn et al. 2013). In terms of size, the specimens from the Ribesalbes-Alcora Basin are smaller than the type population of E. latior , somewhat larger than E. weinfurteri , and fall within the type variability shown for each species (Fig. 9 B View Figure 9 ).
The m 3 has no mesolophid, the posterior crest of the hypoconid is absent, and the posterior crest of the protoconid is medium to long. These characteristics are comparable to those found in E. latior / weinfurteri de Aliveri and E. margueritae , yet still shorter than those of the Buñol population ( Daams and Freudenthal 1974; Hofmeijer and de Bruijn 1988; de Bruijn et al. 2013). With regard to dimensions, they are marginally larger than the E. weinfurteri type population (Fig. 9 C View Figure 9 ).
The M 1 is distinguished by the variability and complexity of the posterior spurs of the anterocone, exhibiting a morphology analogous to that observed in E. latior / weinfurteri populations from Aliveri or Dolnice 1 ( Hofmeijer and de Bruijn 1988; Fejfar 1989). The number of specimens with the paracone spur not attached to the mesoloph is comparable to that observed in E. montanus and E. tremulus , exhibiting a medium mesoloph consistent with that seen in E. montanus ( de Bruijn and Saraç 1991; Lopatin 2004 a). De Bruijn (2009) regards this as one of the distinguishing elements between E. latior and E. weinfurteri . According to the classification system proposed by de Brujin (2009), the material from the Ribesalbes-Alcora Basin’s “ BBB ” morphotype exhibits the characteristic morphologies of E. weinfurteri , including a lingual spur on the anterocone, no connection between mesoloph and metacone, and no paracone spur and mesoloph. The MAB 3 specimen is slightly larger than the E. weinfurteri type population and longer than E. bifidus (Fig. 9 D View Figure 9 ).
A single M 2 has been identified at the MAB 3 locality, and it is characterised by a small posterior paracone spur. This morphology is similar to that described in E. montanus from Keseköy and E. weinfurteri from Sandelzhausen or Bézian ( Bulot 1979; de Bruijn and Saraç 1991; de Bruijn 2009), while in E. latior from Sandelzhausen or E. latior / weinfurteri from Buñol, this crest is more developed ( Daams and Freudenthal 1974; de Bruijn 2009). The protoloph is single, in contrast to the double protoloph observed in E. orhani or E. bifidus ( de Bruijn et al. 2006; de Bruijn 2009). The mesoloph is of medium length, a feature that is analogous to that of E. montanus ( de Bruijn and Saraç 1991) , yet it is comparatively shorter than in E. latior / weinfurteri ( Daams and Freudenthal 1974; de Bruijn 2009). This morphology is another distinguishing factor between E. latior and E. weinfurteri ( de Bruijn 2009; Vasileiadou and Zouros 2012). According to the classification proposed by Bruijn (2009), the material under study falls into the category “ BBB ”: characterised by a simple protoloph, with no connection between the metacone and mesoloph, nor between the paracone spur and the mesoloph. This category is typical of E. weinfurteri . The specimen of MAB 3 is of a size that falls between the type populations of E. weinfurteri and E. latior , coinciding with the variability of the rest of the species shown (Fig. 9 E View Figure 9 ).
The morphology of the third molar exhibits considerable variation, with the axioloph potentially being either complete with a long mesoloph or incomplete with a short mesoloph. The former combination has been observed in E. montanus or early populations of E. latior / weinfurteri ( Daams and Freudenthal 1974; de Bruijn and Saraç 1991), while the latter is exclusively found in the MAB 3 specimens. With regard to biometrics, the M 3 of MAB 3 is larger than the type population of E. weinfurteri and smaller than that of E. medius , which is in agreement with the other species shown (Fig. 9 F View Figure 9 ).
As posited by de Bruijn (2009), in his seminal work on the subject, the material of the genus Eumyarion from the Ribesalbes-Alcora Basin must be ascribed to E. weinfurteri , albeit with a slightly larger size than that of the type population.
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Museu Nacional, Universidade Federal do Rio de Janeiro |
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