Progonomys mauretanicus Coiffait-Martin, 1991

Progonomys mauretanicus Coiffait-Martin, 1991

Fig. 4 J – P View Figure 4

Material and measurements.

one left M 1 (L: 2.05; W: 1.27) ( IPS-PAM 207-01 ); one fragment of right M 1 (W: 1.16) ( IPS-PAM 207-04 ); one left M 2 (L: 1.49; W: 1.32) ( IPS-PAM 207-05 ); one left M 2 (L: 1.39; W: 1.17) ( IPS-PAM 207-06 ); one left m 1 poorly preserved ( IPS-PAM 207-12 ); one right m 2 (L: 1.44; W: 1.25) ( IPS-PAM 207-11 ); one left m 3 (L: 0.98; W: 0.88) ( IPS-PAM 207-00 ).

Description.

M 1. (Fig. 4 J, K View Figure 4 ) The t 1 is displaced posteriorly relative to the t 3. The t 1 bis and the t 2 bis are absent. A short spur on the t 3 is directed toward the t 5 – t 6 intersection. There is no connection between the t 5 and the t 1 or t 3. A spur on the t 6 is directed toward the t 9, but both tubercles are widely separated. The t 4 and t 8 are basally connected by a low, thin ridge. The t 7 is absent. The low, well-developed t 12 is connected to the t 8 but remains separated from the t 9.

M 2. (Fig. 4 L, M View Figure 4 ) The t 1 and t 3 are isolated and oval, the former being larger than the latter. The t 4 is connected basally to the t 8 by a low, narrow ridge. A deep valley separates the t 6 and t 9. The t 7 is absent. There is a small, low t 12 attached to the intersection between the t 8 and t 9.

m 1. (Fig. 4 N View Figure 4 ) The only m 1 is poorly preserved anteriorly and labially. However, it can be distinguished that the labial cingulum reaches the anteroconid. The anteroconid complex is connected to the metaconid – protoconid complex. The protoconid and hypoconid are slightly displaced posteriorly relative to the metaconid and entoconid. The longitudinal spur is absent. The oval-compressed posterior cingulum is slightly displaced lingually.

m 2. (Fig. 4 O View Figure 4 ) The only specimen is somewhat worn. There is no longitudinal spur. The labial cingulum is moderately developed and bears a large labial anteroconid. The small posterior accessory cuspid (c 1) is attached to the hypoconid. Another small, rounded accessory labial cuspid is attached to the protoconid. The posterior cingulum is oval.

m 3. (Fig. 4 P View Figure 4 ) The hypoconid-entoconid pair (posterior complex) is separated from the protoconid-metaconid complex. Neither the labial anteroconid, labial cingulum, nor posterior accessory cuspid (c 1) is present.

Remarks.

Originally, the murid sample from PAM 207 was identified as Paraethomys cf. miocaenicus (see Tesón et al. 2010). However, the separation between the t 6 and t 9 in the M 1 and M 2 allows us to discard its assignment to this genus. By contrast, the examined teeth show features characteristic of the genus Progonomys , including their small size, elongated and narrow shape, the posterior placement of the t 1 relative to the t 3, the connection between the t 4 and t 8, the clear separation of the t 6 and t 9, the absence of t 7, and an overall lack of longitudinal connections.

The PAM 207 sample can be distinguished from Progonomys minus ( Turkey; Sen, 2003), Progonomys morganae (Siwalik; Pakistan; Kimura et al. 2017), Progonomys shalaensis ( China; Qiu and Li 2016), and Progonomys manolo ( Lebanon; López-Antoñanzas et al. 2019) by its larger size. Progonomys hispanicus ( Spain; Michaux 1971), Progonomys debruijni ( Pakistan; Jacobs 1978), and Progonomys yunnanensis ( China; Qiu and Storch 1990) were excluded from the genus Progonomys by Mein et al. (1993). Nevertheless, the studied teeth are larger than those of these three species. By comparison, Progonomys woelferi (Europe; Bachmayer and Wilson 1970) and Progonomys sinensis ( China; Qiu et al. 2004) are distinguished from the studied molars by their larger size.

In North Africa, two species of Progonomys have been recorded: Progonomys cathalai and Progonomys mauretanicus . The specimens from PAM 207 fall within the uppermost part of the size range of Progonomys cathalai from its type locality (Montredon, France; Michaux 1971), with the exception of the m 2, which is distinctly larger than those from Montredon. Similarly, the teeth from PAM 207 reach the upper size limit of Progonomys cathalai from Masía del Barbo 2 B ( Spain; Van de Weerd 1976), Híjar ( Spain; Brandy 1979), and Montredon niveau supérieur ( France; Aguilar 1982). However, the sample from PAM 207 exceeds the size of Progonomys cathalai from Guefaït- 1 ( Morocco; Agustí et al. 2023), Peralejos A ( Spain; Van de Weerd 1976), La Bastida ( Spain; Agustí 1981), Bayraktepe II ( Turkey; Ünay 1981), and Biodrak ( Greece; de Bruijn 1976), among others. Furthermore, the studied specimens display more derived traits than Progonomys cathalai , such as the presence of a slight ridge on the t 6 of M 1. For these reasons, attribution to Progonomys cathalai can be confidently ruled out.

The molars of Progonomys from PAM 207 exhibit diagnostic traits of Progonomys mauretanicus , including the absence of a connection between t 1 and t 5, the presence of a spur on t 3 and a very slight crest on t 6 in M 1, the absence of a connection between t 6 and t 9 in M 2, and a labial cingulum reaching the anteroconid in m 1. Moreover, the size range of the studied molars corresponds to that of Progonomys mauretanicus from its type locality (El Hiout), and Mekhencha, Maatgua, Oued el Arbi, and Bab el Ahmar ( Algeria; Coiffait-Martin 1991), except for the M 1 fragment ( IPS-PAM 207-04 ) and the m 3 ( IPS-PAM 207-00 ), which are slightly smaller. By comparison, the samples of Progonomys mauretanicus from Guergour Ferroudj and Zighout Youcef ( Jaeger 1977; Coiffait-Martin 1991) are slightly larger than those from PAM 207. Considering both morphological and biometric criteria, the specimens from PAM 207 are identified as Progonomys mauretanicus .

The earliest evidence of Progonomys in North Africa dates back to at least 11 Ma, as indicated by the record of Progonomys cathalai in Bou Hanifia 5 (10.9 Ma; Sen 1986). This suggests that the genus may have dispersed simultaneously towards both the northern and southern Mediterranean margins ( Jaeger et al. 1977; Coiffait-Martin 1991; Agustí et al. 2023). The arrival of Progonomys in North Africa from southern Asia likely occurred via the Levant corridor, while its entry into Europe is thought to have followed an eastern Asian route ( López-Antoñanzas et al. 2019). Progonomys mauretanicus is considered a phyletic descendant of Progonomys cathalai in North Africa ( Coiffait-Martin 1991). The species has been recorded from several early and middle Turolian (upper Tortonian – lower Messinian) localities in Algeria, including El Hiout, Bab el Ahmar, Bou Adjeb, Guergour Ferroudj, Maatgua, Ouled el Arbi, Sidi Salem, Zighout Youcef, Sidi Messaoud, and Mekhencha, as well as from the site of As Sahabi in Libya ( Jaeger 1977; Coiffait-Martin 1991; Agustí 2008; Stoetzel 2013).