Subfossil rodents and tenrecs of Children’s Cave, Madagascar
Author
Denys, Christiane
Institut de Systématique, Evolution, Biodiversité (ISYEB) UMR 7205, Muséum National d’Histoire Naturelle, CNRS, Sorbonne Universités, EPHE, Université des Antilles, Paris, France;
Author
Gabriel, Nadine W.
Department of Earth Sciences, Natural History Museum, London, UK;
Author
Lalis, Aude
Institut de Systématique, Evolution, Biodiversité (ISYEB) UMR 7205, Muséum National d’Histoire Naturelle, CNRS, Sorbonne Universités, EPHE, Université des Antilles, Paris, France;
Author
Jenkins, Paulina
Vertebrates Division, Natural History Museum, London, UK
text
Journal of Natural History
2024
2024-07-15
58
25 - 28
796
839
http://dx.doi.org/10.1080/00222933.2024.2370663
journal article
10.1080/00222933.2024.2370663
1464-5262
13219769
Genus
Microgale
Thomas, 1882
Microgale
is a diverse and highly speciose genus, currently understood to be represented in
Madagascar
by 21 species plus one extinct species (
Everson
et al
. 2016
;
Jenkins 2018
;
Jenkins
et al
. 2022
) but suspected to include cryptic species that are in the process of investigation (
Olson
et al
. 2004
; S.M. Goodman and L.E. Olson, pers. comm.). Most of the subfossil material of
Microgale
examined by Major was identified only to the generic level; however it is evident from some of his handwritten label names that he potentially recognised two or more different species. The current study confirmed the presence of two species of
Microgale
,
M. cowani
and
M. pusilla
, among the subfossils in the Children’s Cave. Both species are listed as of Least Concern on the IUCN Red List (
Stephenson
et al
. 2016
).
Figure 8.
Lingual view of right mandibular rami of
Oryzorictinae
. a:
Microgale cowani
NHMUK PV M
103556 with p2–m3; b:
Microgale pusilla
NHMUK PV M
106525 ramus with i2, c–m3, note caniniform p2; c:
Nesogale dobsoni
NHMUK PV M
106705 with p2–m3; d:
Oryzorictes tetradactylus
NHMUK PV M
106728 with c–m3.
Microgale pusilla
and
M. cowani
are distinguished from each other by skull size but also based on dental morphology. The size difference between the two species of
Microgale
found as subfossils in the Children’s Cave is clearly shown in
Table 4
and
Figure 9
, with
M. pusilla
being noticeably smaller than
M. cowani
.
The dentition of
M. pusilla
is markedly smaller than that of
M. cowani
. In
M. pusilla
the talon of the second upper premolar (P3) is absent or reduced to a cingulum and two roots are present, the posterior root being very broad, whereas in
M. cowani
P3 has three roots and a talon is present. The first lower deciduous premolar (dp2) and adult (p2) in
M. pusilla
is caniniform with no anterior accessory cusp and a very small posterior accessory cusp and this tooth has a single root; dp2 and p2 of
M. cowani
have two roots and in p2 the protoconid has an anterior accessory cusp (paraconid) and posterior accessory cusp (hypoconulid). If the teeth are absent, identification may be determined by the corresponding number of root sockets at the P3 or p2 locus.