Subfossil rodents and tenrecs of Children’s Cave, Madagascar

ABSTRACT

Madagascar is famous for its exceptional present and past diversity, yet its Holocene small mammal fauna remains poorly documented. In this work we present the first taxonomic study of the Children’s Cave rodent and tenrec subfossil assemblages collected by Forsyth Major as early as 1895 near Antsirabe in the Central Highlands. We found five rodent species, three endemic and two non-native, as well as six species of tenrecids. This assemblage represents one of the earliest records of Rattus rattus and Mus musculus in the Central Highlands of Madagascar. It is also the first record of Macrotarsomys bastardi in that region, a species that does not currently occur there, and which may indicate a slight environmental change with more bush and forest at the time of the site formation. We find that the native and invasive subfossil specimens do not differ in size and morphology from modern representatives, except for Macrotarsomys. Some proportional differences in rodent taxa are evident between the two Central Highland subfossil assemblages of Children’s Cave and the nearby site of Lavajaza, as well as differences in rodent and tenrecid species composition from other sites in southern parts of Madagascar. Therefore, we are unable to draw any conclusions about the contemporaneity of the Lavajaza and Children’s Cave assemblages nor can we attempt to estimate the relative age of the subfossil fauna.

KEYWORDS:

• Small mammals
• Holocene
• Central Highlands
• taxonomy
• palaeoenvironment

Disclosure statement

No potential conflict of interest was reported by the author(s).

Additional information

Funding

This work was funded by the ATM MNHN 2015 & 2016. We thank all the museum curators who allowed us access to modern and fossil collections. Among them we are especially grateful to C. Funk (ZMB), J. Kerbis Peterhans and S.M. Goodman (FMNH), R. Portela Miguez (NHM), V. Soarimalala and D. Rakotondravony (UADB). We are very grateful to Pip Brewer, Spyridoula Pappa and Neil Adams, who provided very helpful access to the Children’s Cave collection in Fossil Mammals, NHM; and to Kevin Webb and Jonathan Jackson of the Photo Unit, NHM, for photography of the tenrec specimens. We thank Jerry Hooker who cleaned and took the SEM pictures of the upper molar rows of Macrotarsomys specimens. We appreciate the helpful and constructive comments of the reviewers for material improvement of the manuscript.