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New Refs: The Condor



Thought these might be of interest to the list:

Earliest Charadriiform Bird?

Hou Lianhai and Per Ericson describe the humerus of what may be the
earliest charadriiform, said to be similar to several families of
charadriiforms, as well as procellariiforms, but without distinct features
of the latter:

Hou L. and- Ericson, P.G.P. 2002. A middle Eocene shorebird from China.
_The Condor_ 104(4): 896-899. [The title is also given as: "Un ave playera
de China del Eoceno Medio".]

  Abstract:
  "We describe a new species of shorebird, tentatively referred to the
family Charadriidae, from the Huadian Formation (Middle Eocene) in Jilin
Province, China. In general morphology the specimen closely matches that
of an extant charadriid, and corresponds in size to the Killdeer
(Charadrius vociferus). If correctly identified this is the oldest record
of the Charadriidae. The Middle Eocene paleoenvironment of the Huadian
region is thought to have resembled a subtropical swamp.

  "Describimos una nueva especie de ave playera, tentativamente
clasificada como de la Familia Charadriidae, de la Formación Huadian
(Eoceno Medio) en la Provincia de Jilin, China. En términos de morfología
general, el ejemplar coincide mayormente con la morfología de un
charádrido actual, y se asemeja en tamaño a Charadrius vociferus. Si la
identificación es correcta, este representa el registro más antiguo para
la Familia Charadriidae. El paleoambiente del Eoceno Medio de la región de
Huadian se asemejaba probablemente a un pantano subtropical."

  The holotype (IVPP V8323) of the new taxon, *Jiliniornis huadianensis*
comes from Huadian Co., Jilin Prov., China, is a single, complete right
humnerus, exposed in caudal and lateral views. The diagnosis explains the
reasons for referring it to the Charadriiformes:

"As noted by others (Hope, in press) charadriiform birds are difficult to
diagnose based on their general osteology, and this is also true for the
humerus. A charadriiform affinity for *Jiliniornis* is indicated by the
possession of a dorsal tricipital fossa and a well-developed supracondylar
process. The former character differentiates it from all members of the
Anatidae, Presbyornithidae, and Phoenicopteridae. While procellariiform
birds also possess a shallow dorsal tricipital fossa and a well-developed
supracondylar process, *Jiliniornis* lacks the unique torsion of the
humerus of these birds. Furthermore, the supracondylar process (when
present) protrudes less far cranially in charadriiform birds, than in
procellariiforms. The proportions and general appearance of the bone
closely resemble that of a recent charadriid or scolopacid bird."

  The citation for Hope has now been published, in Chiappe and Witmer's
_Above the Heads of Dinosaurs_, "The Mesozoic redord of Neornithes (modern
birds)." Maybe those who have the book can comment.

---

Flight Performance Influenced by Habitat?

Mahler, B. and Tubaro, P.L. 2001. Attenuated outer primaries in pigeons
and doves: A comparative test fails to support the flight performance
hypothesis. _The Condor_ 103(3): 449-454.

  Abstract:
  "Sharp reduction of the inner web of the outer primary feather,
hereafter referred to as the attenuated primary, is present in 54 of about
300 species belonging to the family Columbidae. The flight performance
hypothesis (Goodwin 1983  ) suggests that attenuated primaries improve
flight performance in cluttered habitats, presumably by enhancing
maneuverability. This hypothesis predicts that the evolution of attenuated
primaries should be associated with the use of closed habitats. A
comparative analysis, using the contingent states test (Sillén-Tullberg
1993  ), was made to test this hypothesis. We found that 15 out of 17
independent instances of evolution of attenuated primaries occurred in
clades using closed habitat, but because most species live in closed
habitats, chance alone could explain this result.

  "En 54 de las aproximadamente 300 especies pertenecientes a la familia
Columbidae se observa una abrupta reducción de la lámina interna de la
pluma primaria distal, denominada primaria atenuada de aquí en adelante.
La hipótesis de la performance de vuelo (Goodwin 1983  ) sugiere que las
primarias atenuadas mejoran el desempeño de vuelo en ambientes cerrados,
probablemente por conferir una mayor maniobrabilidad. Esta hipótesis
predice que la evolución de primarias atenuadas debería estar asociada al
uso de ambientes cerrados. Para evaluar esta hipótesis, se realizó un
análisis comparativo usando el método de estados contingentes
(Sillén-Tullberg 1993). Se encontró que 15 de 17 instancias independientes
de evolución de primarias atenuadas ocurrieron en clados de ambientes
cerrados, pero dado que la mayoría de las especies del grupo habitan estos
ambientes, este resultado puede ser explicado simplemente por azar."

  The authors conducted a statistical test of extant columbids regarding
both attenuated primaries (where the feather tapers abruptly on the
trailing (inner) edge) and habitat closure (open areas versus closed
areas). While they found a relation between closed habitat and attenuateds
primaries, the authors could not conclude that the attenuated primary was
an effect of habitat, as there were very few intermediaries or reversals
depending on habitat changes or shifts when the taxa sampled were plotted
on cladograms (Goodwin, 1983). The data does not conclude in favor of
flight performance increased in closed habitats (Goodwin's prediction),
but it appears to be general in nature as an aerial maneuvering ability.
Relationship of attenuated primaries and other bird groups where it is
possible to sample sub-fossil, Quaternary or older feather shapes, will
need to be conducted to test this more generally than Goodwin's columbids.

  Obviously, this has effects in the Mesozoic world, with regards to
lifestyle and habitat preference for animals where we have flight-feather
shapes known, and can test the extant models with extinct forms. Food for
thought.

  Goodwin, D. 1983. _Pigeons and Doves of the World_. [Cornell University
Press (Ithaca, NY)].

  Cheers, 

=====
Jaime A. Headden

  Little steps are often the hardest to take.  We are too used to making leaps 
in the face of adversity, that a simple skip is so hard to do.  We should all 
learn to walk soft, walk small, see the world around us rather than zoom by it.

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