Takahe and Diatryma ( was Re: Diatryma question )

["Matthew Troutman" <m_troutman@hotmail.com>]

> Don't have the ref at hand, but I recall reading somewhere that it's 
now
>suggested that Diatryma might actually have been a leaf eater, based on 
its
>beak structure. Comments, anyone?
>
>


  For a general review check out June, 1995 Natural History for Andors' 
favorable review of this idea.

Diatryma lacks a hooked beak, has less developed flexor tubercles on the 
pedal phalanges, and also has a shortened tarsus; all of these features 
suggests a non-predaceous lifestyle. Diatryma was originally described 
as a predatory bird that rivaled predacious mammals during the Eocene by 
Matthew and Granger. Kurten in the early 1970s dubbed it the " terror 
crane " for both its lifestyle and putative relationships. Witmer and 
Rose in '91 offered a different varient of the predatory hypothesis: 
they performed a functional anaylsis and concluded that diatrymids were 
predatory creatures that may have been bone crushers as an explanation 
for the lack of a rostral hook on the upper mandible. A scavenging 
lifestyle was also concluded by other authors.

The predatory hypothesis was challanged first by Watson in 1976. He 
compared Diatryma with Porphyrio mantelli ( named from fossil forms by 
Richard Owen after Mantell the describer of Iguanodon: a year after 
Owen's description a live Porphyrio was found and it is known in popular 
texts as the takahe ) a leaf-eating ( folivorous ) rail. The skulls both 
show many folivorous adaptations. They share rostral and mandibular 
tomia for an anterior seizing region and posterior slicing region. 
Andors in his 1988 thesis reviewed this favorably and expanded it. He 
concluded that Diatryma was similiar to the takehe in habits and moas 
and elephantbirds in graviportal adaptations. He showed that they share 
a functional hallux and a heavy pes. 

Buffetaut has recently published evidence that Diatryma and Gastornis 
are congeneric. This contradicts L.Martin's and Andor's ideas that 
Gastornis is a member of the Gastornithidae and Diatryma is a member of 
the Diatrymidae within the Gastrornithiformes.

Andors in his various works has concluded that the Gastrornithiformes 
are related to the Anseriformes and are combined together in the 
Anserimorphae. This means not only that they are related to ducks but to 
presbyornids, flamingos, and shorebirds. 

Hopefully this should inform everybody,

MattTroutman








 

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