Venomous mammal
Mammalian venoms form a heterogeneous group with different compositions and modes of action, from four orders of mammals: Eulipotyphla, Monotremata, Primates, and Chiroptera.
Additionally, the feeding secretion of hematophagous specialists (e.g. vampire bats) may be regarded as a specialized subtype of venom.
Whether or not the lack of venom is due to the loss of a basal trait is difficult to determine with current fossil records.
[2] In 2005, Fox and Scott presented evidence of a venom delivery system in late Paleocene fossils found in Alberta.
Fox and Scott argue that the anterior grooves of the upper canines in B. browni serve as venom channels.
[9][10] Euchambersia is an example of a fossil therapsid (a relative of mammals) with grooved teeth, and maxillary fossa to match, indicating the presence of venom glands.
Recent study has identified the gene regulatory network responsible for the development of venom delivery systems in these small mammals.
Shrews cache various prey in a comatose state, including earthworms, insects, snails, and to a lesser extent, small mammals such as voles and mice.
In this context, the shrew venom acts as a tool to sustain a living hoard, thus ensuring food supply when capturing prey is difficult.
Insectivores have an enhanced dependence on vertebrate food material, which is larger and more dangerous than their power to weight ratio would allow, thus requiring an extra asset to overcome these difficulties.
Nowadays any close contact with the animal is rare and restricted to biologists, zookeepers and anglers (who occasionally catch them in fishing lines or nets).
[6] When platypuses attack, they drive their hind legs together with considerable force so that the spurs are embedded in the flesh caught between and if venom is being produced, a few milliliters are injected by repeated jabbing.
Most of the evidence now supports the proposition that the venom system is used by males on one another as a weapon when competing for females, taking part in sexual selection.
These bats produce toxic saliva with anticoagulant properties and have a series of anatomical and physiological adaptations to allow nourishment based solely on blood.
[20] Slow loris venom was known in folklore in their host countries throughout southeast Asia for centuries, but dismissed by Western science until the 1990s.
Slow loris saliva has been shown to be cytotoxic to human skin cells in laboratory experiments without the administration of BGE.
[27] A suite of additional effects of the venom have been documented including mild to permanent disfigurement and mobility loss.
[28] The study of slow loris venom was brought to the public attention in 2012 by the research of the primatologist Prof. K.A.I Nekaris and in her BBC documentary The Jungle Gremlins of Java.
[30][31] Tenrecs, which are similar in appearance to hedgehogs but from a different line of evolutionary descent, may also have separately evolved self-anointing behaviour.
The African crested rat (Lophiomys imhausi) has a mane of long, coarse black-and-white banded hairs which extends from the top of the animal's head to just beyond the base of the tail.
The rat is known to deliberately chew the roots and bark of the poison-arrow tree (Acokanthera schimperi), so-called because human hunters extract a toxin, ouabain, to coat arrows that can kill an elephant.
