Miostrellus cf. noctuloides (LARTET, 1851)

Rosina, Valentina V. & Rummel, Michael, 2019, The Early Miocene Bats (Chiroptera, Mammalia) From The Karstic Sites Of Erkertshofen And Petersbuch 2 (Southern Germany), Fossil Imprint 75 (3 - 4), pp. 412-437 : 428-431

Miostrellus cf. noctuloides (LARTET, 1851)

Text-fig. 8b–f, k, n

M a t e r i a l a n d m e a s u r e m e n t s. Erkertshofen 1: BSP 1962 XIX 4195, left M1, 1.30 × 1.55; BSP 1962 XIX 4198, right M3, 0.85 × 1.55; BSP 1962 XIX 4192, right mnd with m1–2: Lm1–2 2.70, m2 1.40 × 0.80 × 0.90, m1 1.45 × 0.80 × 0.90, Hmdm1 1.70, Hmdm3 1.60; BSP 1962 XIX 4193, right m2, 1.40 × 0.85 × 0.95.

Erkertshofen 2: BSP 1974 XIV 1204, left C sup., 1.00 × 0.90 × 1.65; BSP 1974 XIV 1200, right C inf., 0.65 × 0.75 × 1.30.

Petersbuch 2: PCMRCh4, left C sup., 1.05 × 0.90 × 1.70; PCMRCh23, right P4, 1.10 × 1.15; BSP 1977 XXII 4800, right mnd with m2–3: m2 1.30 × 0.75 × 0.75, m3 1.13 × 0.73 × 0.55, Hmdm1 ≈1.75; BSP 1976 XXII 5361, left M1, 1.35 × 1.45; BSP 1977 XXII 5362, right M1, 1.30 × 1.40; BSP 1977 XXII 5363, right M1, ≈1.25 × 1.40; BSP 1978 XXII 5364, right M1, 1.25 × 1.35.

D e s c r i p t i o n a n d c o m p a r i s o n. The upper molars from Erkertshofen 1 have a well-developed cingulum and paraloph. The crown of the M1 (specimen BSP 1962 XIX 4195; Text-fig. 8c ) show a weak metaloph, thus, the trigon basin is closed. Both upper molars from Erkertshofen 1 are significantly larger than those of M. risgoviensis and smaller than those of Eptesicus aurelianensis ( Tab.8). They differ from the same-sized M. petersbuchensis and M. egeriensis ( Tab. 8) in having paralophs ( Text-fig. 8b, c ; Rosina and Rummel 2012: 471, fig. 5A, Horáček 2001: 140, fig. 24). The M1 from Erkertshofen 1 is very similar to that of M. noctuloides from Sansan in size and in having a small hypocone (compare with Baudelot 1972: 369, pl. II, figs 10, 11; p. 57, fig. 21).

The M3 (specimen BSP 1962 XIX 4198; Text-fig. 8c ) differs from Miostrellus sp. from Forsthart (specimen BSP 1959 XXVII-Ch3, MN 4, Germany) in having a less developed cingulum in the protocone area (compare with Rosina and Rummel 2017: 229, fig. 1e, g). The crown of M3 from Erkertshofen 1 is less compressed in the anteroposterior direction in comparison with E. aurelianensis (specimen SMNS 45744 E1; Ziegler 1994: 113, pl. 5, fig. 4). The isolated third upper molars from Stubersheim 3 are more compressed anteroposteriorly but wider than the M3 from Erkertshofen 1, thus, their crowns morphologically are very similar to those of Plecotus or Corynorhinus ( Ziegler 1994: 113, pl. 5, fig. 7). The M3 from Erkertshofen 1 is very similar to M3 of M. aff. noctuloides from Sandelzhausen (specimen BSP 1959 II 7770, MN 5, Germany; Ziegler 2000: 127, pl. 10, fig. 122) in having a well-developed paraloph and less development of the metacone ( Text-fig. 8b ). The M3 of the nominative M. noctuloides could probably also have a paraloph because this morphological trait is present in the M1 and M2 crowns of this species ( Baudelot 1972: 369, pl. II, figs 10, 11). Nevertheless, the M3 from Erkertshofen 1 is somewhat larger than M. noctuloides from Sansan and from Petersbuch 6 (specimen P6-01046, MN 7/8, Germany; Ziegler 2003: 462, fig. 3(3)).

The crowns of the upper canines from Erkertshofen 2 and Petersbuch 2 (specimens BSP 1974 XIV 1204 and PCMRCh4) are triangular in cross-section, with a welldeveloped cingulum, and without a lingual talon. The posterior and lingual crests are also well-developed, while the buccal crest is less pronounced, and the anterobuccal ridge is rounded ( Text-fig. 8d, e ). The shape of the crowns of the upper canines from Erkertshofen 2 and Petersbuch 2 correspond most closely to Menu’s type A ( Menu 1985: 92, fig. 7). The teeth are very similar to M. risgoviensis ( Rachl 1983: 229, fig. 70a, c) but evidently larger in size ( Tab. 8). They differ from E. aurelianensis from Stubersheim 3 (SMNS 45744 E1; Ziegler 1994: 113, pl. 5, fig. 4) in having a less-developed lingual crest which is located more anteriorly ( Text-fig. 8d, e ). Thus, the upper canines from Erkertshofen 2 and Petersbuch 2 morphologically are most similar to M. aff. noctuloides from Sandelzhausen (specimen BSP 1959 II 7754; Ziegler 2000: 127, pl. 10, fig. 118).

The crown of the P4 from Petersbuch 2 (specimen PCMRCh23) is compressed in the anteroposterior direction which differentiates it from that of Myotis ( Text-fig. 8f ). In contrast to Corynorhinus the P4 from Petersbuch 2 does not show a strongly-developed lingual talon (compare with Rosina et al. 2019: 4, fig. 3B). Nevertheless, a small lingual talon is present. This differentiates the P4 from Petersbuch 2 from that of the modern Plecotus ( Rosina et al. 2019: 4, fig. 3I). It also differs from the P4 of the Miocene Plecotus species in being more compact in form and in being narrower in width ( Text-fig. 8f ; compare with Rosina et al. 2019: 4, fig. 3A). Considering the shape, the P4 from Petersbuch 2 is most similar to Eptesicus or Miostrellus . It differs from M. petersbuchensis ( Rosina and Rummel 2012: 471, fig. 5A) and from M. aff. noctuloides from Sandelzhausen (specimen BSP 1959 II 7756; Ziegler 2000: 127, pl. 10, fig. 119) in having a distinct anterolingual cuspid. The P4 from Petersbuch 2 is similar in size to the P4 of E. aurelianensis which also has an anterolingual cuspid ( Ziegler 1994: 112). However, the P4 of E. aurelianensis is wider than the specimen from Petersbuch 2 (see the measurements of specimen SMNS 45744 F 1 in Ziegler 1994: 112). The crown shape of the P4 from Petersbuch 2 is very similar to those of M. risgoviensis and M. noctuloides , but somewhat larger than both of them ( Tab. 8; compare with specimen Sa. 13.616 from Sansan in Baudelot 1972: 57, fig. 21).

In contrast to Myotis , the crown of the lower canine from Erkertshofen 2 (specimen BSP 1974 XIV 1200) is somewhat compressed in the anteroposterior direction and the cingulid has a higher anterolingual cuspid ( Text-fig. 8k ). Morphologically it is close to Menu’s type B1 ( Menu 1985: 98, fig. 12). The lower canine from Erkertshofen 2 is smaller in size than the lower canines of Miostrellus petersbuchensis ( Tab. 8; compare with Rosina and Rummel 2012: 471, fig. 5E). It is morphologically most similar to M. noctuloides from Sansan and M. noctuloides from Petersbuch 6 ( Tab. 8; Baudelot 1972: 54, fig. 18; specimen NMA P6-1045; Ziegler 2003: 462, fig. 3(2)).

The lower molars from Erkertshofen 1 and Petersbuch 2 are myotodont. The trigonids of the m2 on the mandible fragments (specimens BSP 1962 XIX 4192, BSP 1962 XIX 4193) are compressed, the m1 paralophids are curved while their talonids are much wider than the trigonids ( Text-fig. 8n ). All these traits differentiate the lower molars from Erkertshofen 1 and Petersbuch 2 from the molars of Myotis . The m3 talonid of the specimen BSP 1977 XXII 4800 from Petersbuch 2 is markedly reduced. Morphologically the lower molars from Erkertshofen 1 and Petersbuch 2 are similar to Miostrellus risgoviensis ( Text-fig. 8N ; Rachl 1983: 233, fig. 71), but significantly larger in size ( Tab. 8). They are also larger than M. noctuloides and M. petersbuchensis while smaller than E. aurelianensis ( Tab. 8). Thus, the lower molars from Erkertshofen 1 and Petersbuch 2 are most similar to M. aff. noctuloides from Sandelzhausen in morphology and size ( Tab. 8, specimens BSP 1959 II 7728, 7729; Ziegler 2000: 127, pl. 10, fig. 119).

Figures

Text-fig. 8. a, o – Miostrellus petersbuchensis, Petersbuch 28: a – NMA P28/0335, right maxillary bone with P4–M3, holotype, ventral view; o – NMA P28/0449, right mnd with C inf., p4–m3, occlusal view; b–f, k, n – M. cf. noctuloides: b – BSP 1962 XIX 4198, right M3, Erkertshofen 1, occlusal view; c – BSP 1962 XIX 4195, left M1, Erkertshofen 1, occlusal view; d – PCMRCh4, left C sup., Petersbuch 2, lingual (d1) and occlusal (d2) views; e – BSP 1974 XIV 1204, left C sup., Erkertshofen 2, occlusal (e1) and lingual (e2) views; f – PCMRCh23, right P4, Petersbuch 2, occlusal view; k – BSP 1974 XIV 1200, right C inf., Erkertshofen 2, occlusal view; n – BSP 1962 XIX 4192, right mnd with m1–2; Erkertshofen 1, lateral (n1) and occlusal (n2) views; g – Eptesicus cf. aurelianensis, BSP 1962 XIX 4197, right M2, Erkertshofen 1, occlusal view; h, i – cf. Miostrellus sp., Erkertshofen 2: h – BSP 1974 XIV 1203, left m1, occlusal view; i – BSP 1974 XIV 1207, right P4; j, l, m – Miostrellus cf. petersbuchensis, Petersbuch 2, occlusal views: j – PCMRCh5, left m1; l – PCMRCh7, left p4; m – PCMRCh6, right mnd with m1.