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Labelled Crops of R. rex: Putative Coxae and Trochanters - Ripiphorus rex - male

Labelled Crops of R. rex: Putative Coxae and Trochanters - Ripiphorus rex - Male
Albuquerque, Bernalillo County, New Mexico, USA
April 28, 2012
This is a crop, with labels added, of E. Ruden's image here...posted as a reference for comments related that image and this forum.

[I'll promptly delete or frass, as appropriate. A.S.]

Images of this individual: tag all
Labelled Crops of R. rex: Putative Coxae and Trochanters - Ripiphorus rex - male Labelled Crops of R. rex: Putative Coxae and Trochanters - Ripiphorus rex - male

Vaurie's Coxal Character for R. rex
The arrows in these two images indicate what I think are the correct anatomical interpretations of the trochanter and coxa of this male Ripiphorus rex.
(Note: I have not seen reference images for this genus, so if anyone knows better, please correct me if I'm in error here!)
The trochanter here looks like a small "flap" appressed against the ventral base of the femur.
The coxa looks like a much larger, triangular-to-conical "flap" located inward from the base of the femur and trochanter, and projecting downward.

Vaurie(1) states that a "significant character" for distinguishing R. rex is:

  "the densely hairy elongate projection on the inner side of the front coxae at apex"

It's clear that the coxae in the images here are hairy. What's less clear is what constitutes "densely" hairy. Without a good reference specimen of R. rex to illustrate the typical degree of hairiness in the species (and specimens of different species illustrating the opposing character state) is difficult to say with certainty.

If I had to call it, at first I would have said the hairs look "less than dense". But Edward mentioned elsewhere that this specimen was immersed in alcohol at one point, and then dried. That would tend to mat the hairs and generally diminish the appearance of dense-ness. And after gazing at the images here, I think I can imagine that...before the submersion in alcohol...the coxal hairiness could have been close to that in my specimen below:

And I'd say the coxal projection in the image above qualifies as "densely hairy". So, perhaps up to reasonable variation, the "hairy coxal projection" and "serrate mesotibia" characters are good determinants of R. rex.

Of course, if we do say the coxa are not densely hairy here, than that would indicate the published characters describing R. rex are not consistent with one this specimen seems to have a clearly serrate outer edge on its mesotibia.

coxal projection
Compare my lateral close to yours. Mine's procoxa does not appear to project downward beyond the base of the trochanter. The trochanter is attached very near the apex of a conical coxa.

There is no need to frass these images. There is value added and attribution consistent with the Creative Commons License agreement.

I think your specimen *does* exhibits the hairy coxal projection
Note that, in comparing your lateral close view and mine in the thumbs below:

that the base of the femur in your image is pivoted further back than in mine. So in your lateral image, the view of the coxal projection is obstructed by the base of the fore-femur..whereas in mine there's a substantial gap between the bases of the fore and mid-femora, so the coxal projection can be seen. However, although the coxal projection is blocked in your lateral view, it can be seen clearly in your ventral view below:

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