Afrosoricida


The clade Afrosoricida contains the golden moles of Southern Africa, the otter shrews of equatorial Africa and the tenrecs of Madagascar. These three groups of small mammals were for most of the 19th and 20th centuries regarded as a part of the Insectivora or Lipotyphla, but both of those groups, as traditionally used, are polyphyletic.

Naming

Some biologists use Tenrecoidea or Tenrecomorpha as the name for the tenrec-golden mole clade and regard Afrosoricida as a junior synonym. This is based on the principles of Simpson, summarized by Asher & Helgen to mean that "priority and stability should comprise the overriding principles by which new, high-level taxa are named. Established names for any given clade should not be altered unless the name with precedent unambiguously threatens stability." When "Afrosoricida" was first named in 1998, Afrosorex was a subgenus of Crocidura and McDowell had used the name Tenrecoidea for the same clade of golden moles and tenrecs. Gary Bronner and Paula Jenkins referred to "Afrosoricida" in their chapter in Wilson & Reeder as "... inappropriate since this clade does not include soricids, and could lead to confusion with the soricid subgenus Afrosorex" but still kept it due to their perception that the name was "entrenched in the recent literature" and because of the admittedly confusing history of terms like Tenrecoidea and Tenrecomorpha. Asher & Helgen presented their views on the appropriateness of these and other high-level taxa, including a response to Hedges, who supported keeping "Afrosoricida".

Biology

As a rule, tenrecs and otter shrews tend to be small animals varying from 4 cm to 39 cm in length. There is no pronounced body type since they have evolved to occupy a number of small-bodied, faunivorous niches in Madagascar and mainland Africa. However, certain species bear some ecological similarity to hedgehogs, soricid shrews, or miniature otters. Their coat can vary from smooth to spiny and the coloration of the fur can also vary from brown, gray, to other hues. Most species are also nocturnal and have poor eyesight. Their whiskers are rather sensitive and they can detect very minute vibrations in the ground to locate their prey.
Unusual among placentals, afrosoricids have a cloaca, which is the rear orifice that functions as the opening for the urinary, digestive, and reproductive tracts.

Phylogeny

Traditionally, these two families were grouped with the hedgehogs, shrews and moles in the Lipotyphla. However, there have always been minority opinions suggesting that Tenrecoidea, or at least the golden moles, are not true lipotyphlans. For example, Robert Broom wrote in 1916
that "examination of the skull confirms... that Chrysochloris is not a near ally of Centetes" "and that it is not an Insectivore". These opinions are now supported by many genetic studies indicating an association between tenrecoids and various other African mammals in the Afrotheria.
Tenrecs and golden moles are sometimes considered part of the Afroinsectiphilia, a clade within Afrotheria.

Cladogram of living Afrosoricida

The generally accepted cladogram of living Afrosoricida is:

Species