Acrobatidaefeathertail gliders and pygmy gliders

This small fam­ily of mar­su­pi­als con­tains two gen­era, each with a sin­gle species, Ac­ro­bates pyg­maeus in Aus­tralia and Dis­toechu­rus pen­na­tus in New Guinea. Ac­ro­bates is a glider and has glid­ing mem­brane run­ning from wrist to ankle. Dis­toechu­rus has no mem­brane, but sev­eral as­pects of the bi­ol­ogy of this species sug­gest that their an­ces­tors had a mem­brane and the con­di­tion in Dis­toechu­rus is due to sec­ondary loss.

Ac­ro­batids are small, in fact, Ac­ro­bates is the world's small­est glider at 10-14 gms. Dis­toechu­rus is slightly larger, weigh­ing around 50 gms. Both species feed pri­mar­ily on nec­tar, and they both have long, brush-tipped tongues for re­treiv­ing nec­tar and pollen from flow­ers. They may also eat some in­sects.

These species can be char­ac­ter­ized as mem­bers of the Diprotodon­tia with long, stiff hairs on ei­ther side of tail, that give it a feather-like ap­pear­ance. This may orig­i­nally have been an adap­ta­tion for steer­ing while glid­ing. Like other mem­bers of their order, ac­ro­batids are syn­dacty­lous and diprotodont.

The den­tal for­mula of ac­ro­batids is 3/2, 1/0, 2-3/3, 3/3. Their mo­lars are bun­odont and quadritu­ber­cu­lar; the upper pre­mo­lars are sec­odont.

In the past, ac­ro­batids have been clas­si­fied with the bur­ramyids. Re­cent ev­i­dence sug­gests that they may be more closely re­lated to Tar­sipes.

Lit­er­a­ture and ref­er­ences cited

Feld­hamer, G. A., L. C. Drick­amer, S. H. Vessey, and J. F. Mer­ritt. 1999. Mam­mal­ogy. Adap­ta­tion, Di­ver­sity, and Ecol­ogy. WCB Mc­Graw-Hill, Boston. xii+563pp.

Mar­shall, L. G. 1984. Monotremes and mar­su­pi­als. Pp 59-115 in An­der­son, S. and J. Knox Jones, eds, Or­ders and Fam­i­lies of Re­cent Mam­mals of the World. John Wiley and Sons, NY. xii+686 pp.

Stra­han, R. (ed.). 1995. Mam­mals of Aus­tralia. Smith­son­ian In­sti­tu­tion Press, Wash­ing­ton, D.C. 756 pp.

Vaughan, T. A. 1986. Mam­mal­ogy. Third Edi­tion. Saun­ders Col­lege Pub­lish­ing, Fort Worth. vi+576 pp.

Vaughan, T. A., J. M. Ryan, N. J. Czaplewski. 2000. Mam­mal­ogy. Fourth Edi­tion. Saun­ders Col­lege Pub­lish­ing, Philadel­phia. vii+565pp.

Wil­son, D. E., and D. M. Reeder. 1993. Mam­mal Species of the World, A Tax­o­nomic and Ge­o­graphic Ref­er­ence. 2nd edi­tion. Smith­son­ian In­sti­tu­tion Press, Wash­ing­ton. xviii+1206 pp.

Con­trib­u­tors

Phil Myers (au­thor), Mu­seum of Zo­ol­ogy, Uni­ver­sity of Michi­gan-Ann Arbor.

Glossary

bilateral symmetry

having body symmetry such that the animal can be divided in one plane into two mirror-image halves. Animals with bilateral symmetry have dorsal and ventral sides, as well as anterior and posterior ends. Synapomorphy of the Bilateria.

chemical

uses smells or other chemicals to communicate

endothermic

animals that use metabolically generated heat to regulate body temperature independently of ambient temperature. Endothermy is a synapomorphy of the Mammalia, although it may have arisen in a (now extinct) synapsid ancestor; the fossil record does not distinguish these possibilities. Convergent in birds.

motile

having the capacity to move from one place to another.

sexual

reproduction that includes combining the genetic contribution of two individuals, a male and a female

tactile

uses touch to communicate