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Re: Fossil emus

Many thanks to Darren (and to Tim) for this info.  Isn't it wonderful what
you can learn about your local overburden from the other side of the world?


-----Original Message-----
From: Tim Williams <twilliams_alpha@hotmail.com>
To: dinosaur@usc.edu <dinosaur@usc.edu>
Date: Thursday, 22 January 2004 2:22
Subject: Fossil emus

>The honorable Darren Naish requested that I forward this to the list.
>>Emus have quite a good fossil record with definite members
>>of the Dromaiinae being known as early as the Pliocene
>>(note that in this discussion I follow most other recent
>>authors in regarding Dromaiinae and Casuariinae as sister-
>>taxa within the Casuariidae). Sibley & Ahlquist (1990)
>>proposed on the basis of DNA-DNA hybridisation that
>>dromaiines and casuariines diverged during the Late
>>Oligocene (c. 25 mya). Patterson & Rich (1987) reviewed
>>all fossil emus and this work should be your first stop if
>>you're interested in the fossil history of the group.
>>_Emuarius_ from the Late Oligocene to Late Miocene of
>>Australia - originally placed within _Dromaius_ - has more
>>recently been argued to be a basal dromaiine outside
>>_Dromaius_ (see Boles 1992, 1997, 2001). _Emuarius_
>>combines features of cassowaries (e.g., femur, skull) with
>>those of emus (e.g., feet, tibiotarsus) and consequently its
>>generic name is a deliberate combination of 'emu' and
>>'_Casuarius_': on occasion Boles has even referred to
>>_Emuarius_ as a 'cassomu' or 'emuwary'. Two species are
>>presently known: _D. gidju_ from the Late Oligocene-early
>>Late Miocene of Riversleigh, Queensland; Early Miocene
>>Wipajiri Formation of South Australia; and Late Miocene of
>>Alcoota, Northern Territory, and _E. guljaruba_ from the
>>Late Oligocene Etadunna Formation of South Australia.
>>The oldest known casuariines (cassowaries) are from the
>>Pliocene of Papua (Plane, 1967). Other fossil cassowaries
>>are known from the Pleistocene of New South Wales and
>>Charles De Vis named several fossil emu species, all from
>>the Pleistocene Darling Downs of Queensland, during the
>>1880s and 90s. _Dromaius patricius_ was based on an
>>assortment of bones, not all of which were avian: only a
>>partial tibiotarsus referred to this species is definitely from
>>an emu (De Vis, 1888, 1892, 1905) and it was shown by
>>Patterson & Rich (1987) to be indistinguishable from the
>>corresponding bone of _D. novaehollandiae_. De Vis
>>regarded _D. patricius_ as appreciably larger than _D.
>>novaehollandiae_ but in fact all the emu material of _D.
>>patricius_ overlaps in size with that of _D.
>>novaehollandiae_. A second species, _D. gracilipes_ (based
>>on a distal left tibiotarsus (De Vis, 1892)), is also
>>indistinguishable from the corresponding element of _D.
>>novaehollandiae_. _Metapteryx bifrons_, regarded by De
>>Vis (1892) as a giant kiwi and based on a partial left
>>tarsometatasus, is also a fossil emu and was shown by
>>Patterson & Rich (1987) to, again, be indistinguishable
>>from _D. novaehollandiae_.
>>What appears to be the only valid species of entirely fossil
>>emu, _D. ocypus_, is from the Pliocene Mampuwordu
>>Sands of Lake Palankarinna, South Australia (Miller, 1963).
>>Only known from a damaged tarsometatarsus (though a
>>partial femur and partial tibiotarsus were later referred to
>>this species), _D. ocypus_ is smaller than both Pleistocene
>>and modern _D. novaehollandiae_ and it differs from _D.
>>novaehollandiae_ in having a more strongly convex
>>proximal intercotylar region.
>>Finally, the extant species _D. novaehollandiae_ is known
>>from abundant Pleistocene records and there are even
>>questionable Late Pliocene sites yielding this species (e.g.,
>>Cooper Creek, SA; Lake Kanunka, SA). Pleistocene sites
>>that have yielded fossil _D. novaehollandiae_ include
>>Darling Downs (Queensland) as discussed above, Bingara
>>(NSW), Lake Callabonna (SA), Lake Menindee (NSW),
>>Naracoote (SA), Thorlindah (Queensland), and Wombeyan
>>Quarry (NSW). For the full details on all of these records
>>see Patterson & Rich (1987). These fossils show that _D.
>>novaehollandiae_ had appeared by the start of the
>>Pleistocene at least (1.6 mya) and possibly by the Late
>>Pliocene (somewhere around 2-3 mya).
>>Several Pleistocene adult _D. novaehollandiae_ specimens
>>were smaller than living emus. This suggests that this
>>species underwent some periods of dwarfism in its history,
>>perhaps due to climatic or other palaeoenvironmental
>>Fossils of both historically extinct emus, the King Island
>>(_D. ater_) and Kangaroo Island emus (_D. baudinianus_),
>>are known but are poorly dated: they are probably Holocene
>>but may be Late Pleistocene. How old these two species are
>>is unknown but it is likely that both were recently evolved
>>island endemics: Patterson & Rich (1987) write 'We favour
>>the idea that speciation on King and Kangaroo Island could
>>have taken place in very little time geologically speaking.
>>Strong selection for dwarfism quite likely occurred after
>>these emus became isolated at the beginning of the last
>>interglacial (i.e., the Holocene)' (p. 99). Incidentally both
>>_D. ater_ and _D. baudinianus_ can be distinguished from
>>_D. novaehollandiae_ on the basis of skull characters.
>>The taxonomic status of the (also extinct) Tasmanian emu
>>(_D. diemenensis­_) is uncertain and whether this form was
>>part of _D. novaehollandiae_ or a distinct taxon remains
>>debated. Tasmanian emu fossils are known from the
>>Pleistocene (Scott, 1932). While the body size of the
>>historical Tasmanian emu population is controversial (there
>>is uncertainty as to whether it was a dwarf relative to _D.
>>novaehollandiae_), the Pleistocene Tasmanian fossils are
>>the same size as extant _D. novaehollandiae_.
>>Refs --
>>Boles, W. E. 1992. Revision of _Dromaius gidju_ Patterson
>>and Rich 1987 from Riversleigh, northwestern Queensland,
>>Australia, with a reassessment of its generic position.
>>_Science Series Natural History Museum of Los Angeles
>>County_ 36, 195-208.
>>Boles, W. E. 1997. Hindlimb proportions and locomotion of
>>_Emuarius gidju_ (Patterson & Rich, 1987) (Aves:
>>Casuariidae). _Memoirs of the Queensland Museum_ 41,
>>Boles, W. E. 2001. A new emu (Dromaiinae) from the Late
>>Oligocene Etadunna Formation. _Emu_ 101, 317-321.
>>De Vis, C. W. 1888. A glimpse of the post-Tertiary
>>avifauna of Queensland. _Proceedings of the Linnean
>>Society of New South Wales_ 3, 1277-1292.
>>De Vis, C. W. 1892. Residue of the extinct birds of
>>Queensland as yet detected. _Proceedings of the Linnean
>>Society of New South Wales_ 6, 437-456.
>>De Vis, C. W. 1905. A contribution of the extinct avifauna
>>of Australia. _Annals of Queensland Museum_ 6, 3-25.
>>Miller, A. H. 1963. Fossil ratite birds of the late Tertiary of
>>South Australia. _Records of the South Australia Museum_
>>13, 413-420.
>>Patterson, C. & Rich, P. V. 1987. The fossil history of the
>>emus, _Dromaius_ (Aves: Dromaiinae). _Records of the
>>South Australia Museum_ 21, 85-117.
>>Plane, M. D. 1967. Stratigraphy and vertebrate fauna of the
>>Otibanda Formation, New Guinea. _Bureau of Mineral
>>Resources, Geology and Geophysics (Australia) Bulletin_
>>184, 1-64.
>>Scott, H. H. 1932. The extinct Tasmanian emu.
>>_Proceedings of the Royal Society of Tasmania_ 1932, 103-
>>Sibley, C. G. & Ahlquist, J. E. 1990. _Phylogeny and
>>Classification of the Birds: A Study in Molecular
>>Evolution_. Yale Univ. Press (New Haven & London).
>>Darren Naish
>>School of Earth & Environmental Sciences
>>University of Portsmouth UK, PO1 3QL
>>email: darren.naish@port.ac.uk
>>tel: 023 92846045
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