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Selmes absurdipes, New Genus, New Species,
a Sandcoleiform Bird from the Oil Shale of
Messel (Germany, Middle Eocene)
ABSTRACT
Selmes absurdipes, new genus, new species, is established for
two fossil specimens from Messel. The pamprodactyl foot, with
unusually short toes and comparatively long tarsometatarsus and
tibiotarsus, is the most characteristic feature of the new genus.
Sandcoleiformes were not confined to North America and had a
considerable morphological radiation. It might be appropriate to
combine Sandcoleiformes and Coliiformes.
Introduction
Surprisingly, the great majority of fossil birds from the lake
deposits of Grube Messel are land birds. Many of them are difficult
to classify with extant taxa even on the ordinal level (Peters,
1991, 1992). Houde and Olson (1992) established the order
Sandcoleiformes for a variety of species from the Eocene
of North America. Some of these birds were previously assigned
to various other higher taxa. Subsequently, an examination
of several Messel birds revealed that the new order was not
confined to North America. Two specimens of a supposed species
of Sandcoleiformes from Messel are described herein. The
anatomical terminology used is after Baumel et al. (1993) unless
otherwise indicated.
ACKNOWLEDGMENTS.—I am indebted to S. Rietschel, Landessammlungen
fur Naturkunde, Karlsruhe, who kindly lent
the paratype of Selmes absurdipes. I wish to thank Storrs Olson,
Peter Houde, and an anonymous reviewer for their critical
review of the manuscript.
D. Stefan Peters
D. Stefan Peters, Forschungsinstitut Senckenberg, Senckenberganlage
25, D-60325 Frankfurt am Main, Germany.
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Systematics
SANDCOLEIFORMES
SANDCOLEIDAE
REMARKS.—Placed within order and family by the following
characters: apertura nasi ossea large and holorhinal; rostrum
maxillae distal to the nostrils rather short; mandibula curved
(ventrally concave, dorsally convex) and with a short symphysis;
fenestrae mandibulae absent; furcula thin and lacking a hypocleideum;
olecranon short and blunt; papillae remigiales absent;
processus intermetacarpalis absent; os metacarpale majus
and o. m. minus subequal in distal extent; the three proximal
phalanges of digit IV very short; phalanges unguales large and
with strong flexor tubercles.
Selmes, new genus
FIGURES 1-3
TYPE SPECIES.—Selmes absurdipes, new species, the only
known species of the genus.
ETYMOLOGY.—Anagram of Messel. Selmes should be treated
as masculine in gender.
DIAGNOSIS.—The new genus differs from all known sandcoleiform
genera by the unique morphology of its hind limbs.
The tarsometatarsus is rather slender and is markedly longer
than the longest toe; its distal end is only slightly broadened,
approaching the condition of Coliiformes. Not only the proximal
phalanges of toe IV but also the proximal two phalanges of
toe III and the proximal phalanx of toe II are extremely short.
Toes III and IV are of almost equal length. The foot is pamprodactyl
and possibly was facultatively anisodactyl.
In addition, Selmes differs from Sandcoleus Houde and Olson,
1992, by having a comparatively shorter and thicker bill; it
differs from Chascacocolius Houde and Olson, 1992, by having
neither long processus retroarticulares mandibulae nor a marked
epicondylus of humerus nor processus intermetacarpales.