Democricetodon FAHLBUSCH, 1964

Jovells-Vaqué, Sílvia, Ginestí, Montserrrat & Casanovas-Vilar, Isaac, 2017, Cricetidae (Rodentia, Mammalia) From The Early Miocene Site Of Els Casots (Vallès-Penedès Basin, Catalonia), Fossil Imprint 73 (1 - 2), pp. 141-154 : 143-146

Genus Democricetodon FAHLBUSCH, 1964

Democricetodon hispanicus FREUDENTHAL, 1967 Pl. 1, Figs 1–5

1993 Democricetodon aff. hispanicus; Agustí and Llenas, p. 70.

1993 Fahlbuschia sp. ; Agustí and Llenas, p. 70 (? partim).

M a t e r i a l f r o m e l s C a s o t s l e v e l 7 2. 3 M3

(IPS 45092, IPS 45093, IPS 94650); 1 m 1 (IPS 19522) .

M a t e r i a l f r o m e l s C a s o t s l e v e l 7 3. 1 M3 (IPS 19503); 8 m 1 (IPS 19517, IPS 45051, IPS 45053 – IPS 45058) ; 7 m 3 (IPS 19519, IPS 94653, IPS 94698, IPS 94700, IPS 94701, IPS 94637, IPS 94638) .

M a t e r i a l f r o m e l s C a s o t s l e v e l 7 4. 10 M1 (IPS 19491, IPS 45000 – IPS 45008); 15 M2 (IPS 19491, IPS 45006 – IPS 45008, IPS 19475, IPS 45019 – IPS 45027, IPS 19490) ; 5 M3 (IPS 45006, IPS 45008, IPS 45027, IPS 94602, IPS 94652) ; 12 m 1 (IPS19481, IPS 45040 – IPS 45050) ; 15 m 2 (IPS 19474, IPS 45059 – IPS 45071, IPS 94609) ; 8 m 3 (IPS 45069, IPS 19473, IPS 45082 – IPS 45087) .

M e a s u r e m e n t s. See Tables 1–3.

D e s c r i p t i o n. M1. The M 1 have three roots. The most mesial of them is cylindrical and located below the anterocone, a second one is positioned at the postero-labial corner of the molar and the last one is flattened and occupies the lingual part of the tooth. All studied specimens have a simple anterocone, except one in which this cusp is slightly subdivided (IPS 45001). The arms of the anteroph are well developed, and enclose the anterior valleys. The anterophule is simple and placed somewhat lingually. The protosinus is relatively reduced. The protolophule consists of a single posterior arm that joins the entoloph behind the protocone. IPS 45000 exhibits a double protolophule with a very low anterior arm. A vestigial anterior arm is also present in IPS 45008 (Pl. 1, Fig. 1), but it is interrupted before reaching the paracone. In some specimens, there is a short ectoloph on the paracone. The mesoloph is of medium length in six out of nine specimens; in the remaining ones it is short. The metalophule consists of a posterior arm only that connects the metacone with the posteroloph just behind the hypocone. The sinus is always wide and transverse. The posterosinus is highly reduced and closed by the posteroloph. The sinus is closed by well-developed cingulum .

M2. The M 2 have two roots (mesial and distal) which are flattened. The anteroloph shows a long and high labial arm that encloses the narrow anterosinus. The protosinus is vestigial and is also closed by a much lower lingual arm of the anteroloph. In six out of 13 specimens, the protolophule consists of an anterior arm and a posterior one, which is connected to the entoloph posteriorly to the protocone. In the other nine specimens, the posterior arm of the protolophule is incomplete (for example in IPS 45008; Pl. 1, Fig. 1), being interrupted before merging with the paracone. In nine out of 15 specimens, the mesoloph is long, while it is of medium length in five, and short in only one. When long, the labial end of the mesoloph may end in a small mesostyle at the edge of the mesosinus or it may curve distally to contact the anterior wall of the metacone. The sinus is transverse and closed by a cingulum. The metalophule is short and simple, being transverse in half of the specimens and anterior to the hypocone in the remaining ones. The posteroloph closes the posterosinus, while the mesosinus is closed by a low cingulum .

M3. The M3 have two cylindrical roots. These molars show a characteristic button shape and a reduced distal half. The anterosinus is almost closed by the well-developed labial arm of the anteroloph. As in the M2, the protosinus is highly reduced and is closed by a low lingual arm of the anteroloph. The hypocone is rotated antero-labially and connects with the protocone by means of a neo-entoloph. The protolophule consists of a single anterior arm in all specimens. The metacone cannot be clearly distinguished and it connects with the hypocone through a short metalophule. The mesosinus is closed by a cingulum which is continuous with the posteroloph. The posterosinus is reduced to a tiny circular valley.

m1. They have two cylindrical roots, one located below the anteroconid and the other one below the posterior part of the teeth. The anteroconid is simple and rounded. The mesolophid is variable in length, being short in six out of 21 specimens, of medium length in 12 and long in the remaining ones. The anterior valleys are closed by the arms of the anterolophid, which are quite low. The sinusid is wide and mostly points forwards, although it may be transverse in a few specimens. This valley and the mesosinusid are closed by a low cingulid. The hypolophulid is very short and merges with the entolophid anteriorly to the hypoconid. The metalophulid, is absent in IPS 19481 (Pl. 1, Fig. 2) and in IPS 45055 it is interrupted before reaching the protoconid. In the other specimens, the metalophulid is very short and anterior to the protoconid. The posterolophid closes the posterosinusid, reaching the posterior wall of the entoconid .

m2. These teeth have two cylindrical roots (mesial and distal). The lingual anterolophid and the anterosinusid are reduced. The protosinusid is closed by the labial arm of the anterolophid. The mesolophid is short in nine out of 15 specimens and absent in two, while in the remaining four it is of medium length. The remaining morphological features replicate those of the m1.

m3. The specimens present two cylindrical roots (mesial and distal). The anterior valleys are relatively reduced and they appear to be closed by the arms of the anterolophid which are quite low. The metaconid is prominent and connects with the anterolophid by means of an extremely short metalophulid. The mesolophid is absent in all the specimens. The entoconid is greatly reduced and is integrated into the hypolophulid, which is well developed and wide. The sinusid is generally open and points backwards. The posterosinusid is reduced and completely closed by the posterolophid which is very high. The mesosinusid is also closed by a high ridge that departs from the posterior wall of the metaconid.

D i s c u s s i o n. The specimens from els Casots fit within the size range of Democricetodon hispanicus (Textfig. 2; see also Van der Meulen et al. 2003). However, a few somewhat larger dental elements (M2, and some m1, m2 and m3) previously led Agustí and Llenas (1993) to ascribe the material to D. aff. hispanicus. Nevertheless, the described material perfectly corresponds in morphology with D. hispanicus and only very few specimens are slightly above the upper size range of the species. Democricetodon hispanicus is distinguished from chronologically and geographically close species such as D. decipiens FREUDENTHAL et DAAMS, 1988, D. franconicus FAHLBUSCH, 1966 and D. koenigswaldi ( FREUDENTHAL, 1963) by its smaller size ( Van der Meulen et al. 2003). It further differs from D. decipiens by its longer mesolophids and from D. koenigswaldi by the predominance of transverse or anterior metalophules in the M2 ( Van der Meulen et al. 2003). In els Casots material, the mesolophs are predominantly of medium length or long in the M1 and M2. In the lower molars, the mesolophid is predominantly long in the m1 and short in the m2. The protolophule is predominantly posterior in the M1 and double in the M2, with a generally better-developed anterior arm. The metalophule is always posterior to the hypocone in the M1 and anterior to the hypocone or transverse in the M2. All these characters fit with D. hispanicus, although long mesolophs/ids are somewhat more frequent in the material from other localities (see Freudenthal and Daams 1988, Van der Meulen et al. 2003). Democricetodon decipiens is distinguished from the material of els Casots by the presence of predominantly short mesolophids in the lower molars, a situation that in the described material only occurs in the m2. Democricetodon hispanicus occurs in other sites of the Vallès-Penedès Basin such as Les Cases de la Valenciana (Jovells-Vaqué et al. in press) and Can Martí Vell 1 and 2 ( Agustí 1981, 1983), which are also included in the Subirats lacustrine unit. The material of all these sites is very similar in size and morphology, which could presumably be due to their similar age.