BOOK REVIEW
ARCHAEOPTERYX. DER URVOGEL VON SOLNHOFEN, by Peter Wellnhofer, 2008. Munich, Germany:
Verlag Dr. Friedrich Pfeil, 256 pp., !78.00, ISBN 978-3-89937-076-8.
With the possible exception of Tyrannosaurus rex, Archaeopteryx is
arguably the most widely known extinct animal. Due to exceptional
preservation in the fine-grained limestones of the Upper Jurassic
Solnhofen Formation of Bavaria (Germany), most of the available
skeletons of this taxon retain distinct impressions of feathers. Conse-
quently, despite the many ?reptilian? features of its skeleton, the avian
affinities of Archaeopteryx were at once apparent. The first reported
specimen, a single feather, was discovered in 1861 ? little more than a
year after the publication of Darwin?s On the Origin of Species in
November 1859. A second specimen, an almost complete skeleton now
housed in the Natural History Museum in London, was also found in
1861. With subsequent discoveries and studies, Archaeopteryx became
firmly established as the classic example of an evolutionary ?missing
link? ? a veritable ?icon of evolution.?
Peter Wellnhofer?s new book is a treasure trove of information on
Archaeopteryx, the history of its study, and its provenance. Although it
is ostensibly aimed at an educated general readership, the specialist will
gain a tremendous amount of information from this volume. Along with
the late John H. Ostrom (to whose memory the book is dedicated),
Peter Wellnhofer has long been the leader in the study of Archaeopter-
yx, and he has authored the first anatomical descriptions of several of
the more recent finds. Thus, Wellnhofer brings unrivalled expertise to
an account of this fascinating, complex subject.
Following a brief general introduction, the second chapter of the
book provides detailed accounts of the history of the small town of
Solnhofen and its environs as well as the history of quarrying operations
in the eponymous Solnhofen Formation. The limestones of this strati-
graphic unit have been popular as high-quality building material since
Roman times. A dramatic increase in the demand for these rocks came
as the result of the invention of lithography by Alois Senefelder in 1798.
This printing technique utilizes the fact that water and oil do not mix.
Lithography originally involved drawing an image with an oil-based
medium on a smooth limestone surface, which readily absorbs both oil
and water. After the oil had penetrated the porous surface of the stone
a water-based solution of gum arabic was applied to seal non-oily sur-
face areas. The stone was then inked with a roller; the oil-impregnated
areas accepted the ink whereas the adjoining sealed areas rejected it
and became the background. In this manner, hundreds of copies could
be printed from a single slab. The Solnhofen limestones proved unique-
ly suited for Senefelder?s printing technique. Following Senefelder?s
pioneering efforts, lithography in its original form remained in wide
use for almost a century until its replacement by simpler and cheaper
processes. Today, lithography is only used by a few skilled artisans for
the reproduction of high-quality artwork.
The third chapter of Wellnhofer?s book discusses the geology of the
Solnhofen Formation. During the Late Jurassic, specifically the early
Tithonian, the finely laminated limestones of this unit were laid down in
basins or lagoons between reefs formed mainly by sponges and asso-
ciated microorganisms on a shallow marine platform along the northern
edge of the Tethys.
The fossils from the Solnhofen Formation represent death assem-
blages. At the bottom of the depositional basins, stagnant, hypersaline,
and oxygen-poor water created conditions hostile to benthic life. A
warm, subtropical climate prevailed during the deposition of the Soln-
hofen limestones and, through substantial evaporation, would have con-
tributed to an increase in water salinity. Occasional, possibly seasonal
mixing of this toxic bottom layer with the less saline, better oxygenated
surface waters through storms led to the demise of countless nektonic
and planktonic animals, which sank to the bottom and were quickly
covered by fine calcareous mud. Heavy seasonal rainfall would have
washed animal cadavers and plant debris from adjoining land into the
basins. Powerful storms may have blown flying animals out to sea where
they eventually drowned. The terrestrial plant fossils from the Solnho-
fen Formation mostly comprise dry-adapted conifers, along with a few
benettitaleans and cycads, and are consistent with warm, semi-arid cli-
matic conditions. Ferns and other plants requiring more humid condi-
tions are absent.
Chapter 4 presents a comprehensive synopsis of the great diversity of
animals and plants from the Solnhofen Formation along with extensive
discussion of the history of their exploration. In 1616, the first identifi-
able illustrations of Solnhofen fossils appeared in a catalogue of curios-
ities belonging to a Nuremberg collector named Basilius Besler. The
Solnhofen limestones achieved international recognition when Georges
Cuvier identified the first pterosaur (Pterodactylus) in 1801, and the
subsequent discovery of Archaeopteryx consolidated that reputation.
Today, the Solnhofen Formation is renowned as one of the richest fossil
Lagersta?tten in the world and provides a unique window into the diver-
sity of Late Jurassic life. Wellnhofer cites 262 currently recorded genera
of marine animals and algae, but this number does not include the
diverse microfossils, most of which remain undescribed. Although less
common, terrestrial animals comprise over 150 described species of
insects and a variety of reptiles including pterosaurs, the small non-
avian theropod Compsognathus, and Archaeopteryx. (An alleged record
of a temnospondyl amphibian proved to be based on the tail of a turtle.)
Chapters 5?7 provide a detailed review of the history of discovery,
anatomy, paleobiology, phylogenetic position, taxonomy, and taphono-
my of Archaeopteryx. In addition to the single feather, on which Meyer
(1861) based the binomen Archaeopteryx lithographica, nine skeletons
or parts of skeletons have been identified to date. An additional speci-
men, disarticulated remains of a skeleton referred to Archaeopteryx sp.,
was collected from the stratigraphically slightly younger Mo?rnsheimer
Beds at Daiting. Unfortunately, this important fossil has disappeared
into unidentified private hands and only a single colored cast remains
available for scientific examination.
Chapter 5 discusses the history of discovery and presents information
concerning the structure of each individual specimen. The former often
involves fascinating stories replete with the kind of skulduggery more
commonly associated with archaeological treasures. Unlike other
German states, Bavaria never passed legislation to protect its paleonto-
logical resources and thus a thriving worldwide trade in Solnhofen
fossils has established itself over the years. Any newly discovered skele-
tons of Archaeopteryx would now command millions of euros, making
them unaffordable for even the largest natural history museums.
Wellnhofer distinguishes two valid species of Archaeopteryx,
A. lithographica Meyer, 1861 and A. bavarica Wellnhofer, 1993. Like
many early type specimens, the holotype of A. lithographica ? the
isolated feather ? is now inadequate for taxonomic purposes, and
the first reported skeleton (the London specimen) should be officially
designated as the neotype. Except for the holotype of A. bavarica,
Wellnhofer regards all other named genera and species of Urvo?gel from
the Solnhofen Formation as representing various ontogenetic stages of
A. lithographica. He differentiates A. bavarica primarily on the basis
of its limb proportions and the proportionately greater length of its
primary and tail feathers.
Chapter 6 presents a detailed, well-illustrated account of the skeleton
and plumage of Archaeopteryx and examines various aspects of its
paleobiology. Wellnhofer reconstructs Archaeopteryx as primarily ter-
restrial and insectivorous in its habits, but considers it capable of
moving up into the branches of bushes and trees where its feet would
have allowed it to gain a perch. He also regards Archaeopteryx as an
active flyer although as less capable in this respect than later, more
derived birds.
Chapter 7 provides an overview of the phylogenetic significance of
Archaeopteryx. Although Wellnhofer clearly favors the almost
Journal of Vertebrate Paleontology 29(1):310?311, March 2009
# 2009 by the Society of Vertebrate Paleontology
310
universally accepted hypothesis of a theropod origin for birds he briefly
reviews the various alternatives advanced and dismissed over the years.
Chapters 8?10 explore broader issues of the origin and early evolu-
tionary history of birds with emphasis on information provided by Ar-
chaeopteryx. Chapter 8 explores the origin of avian flight based on the
longstanding debate revolving around the ?from the trees down? vs. the
?from the ground up? scenario. While generally presenting a compre-
hensive discussion, Wellnhofer does not mention the recent work by
Kenneth P. Dial and his students at Montana State University, which, at
least in this reviewer?s opinion, should finally settle the controversy.
Chapter 9 reviews the origin of feathers. Wellnhofer notes the presence
of filamentous body covering or feathers in various taxa of non-avian
theropod dinosaurs from the Lower Cretaceous of Liaoning (China).
Based on his own observations of the Chinese fossils, he explicitly rejects
recent claims that these structures merely represent degraded collagen
fibers that were removed from their original context by postmortem
maceration. Finally, Chapter 10 provides a concise overview of the Me-
sozoic fossil record of birds and early avian evolution. Although Well-
nhofer includes an illustration featuring a cladogram of Mesozoic birds
he only briefly notes some of the associated character transformations.
Somewhat unexpectedly, the text ends with a short poem on Archae-
opteryx by the contemporary German poet Elke Langstein-Ja?ger. The
extensive bibliography provides a helpful introduction to the substantial
body of literature on Archaeopteryx and the origin of birds.
The book is richly illustrated with drawings and photographs.
Particularly noteworthy are a series of specimen photographs taken by
Helmut Tischlinger under long-wave UV light; by greatly enhancing the
contrast between the bones and the limestone matrix, this mode of
illumination reveals much otherwise invisible detail.
Peter Wellnhofer?s new book represents the most detailed, authorita-
tive account on Archaeopteryx published to date and belongs on the
bookshelf of every serious student of vertebrate evolution. It is to be
hoped that an English translation will soon give it the wide international
readership it so richly deserves.
HANS-DIETER SUES
National Museum of Natural History
Smithsonian Institution
MRC 106, P.O. Box 37012
Washington, DC 20013-7012
LITERATURE CITED
Meyer, H. von. 1861. [Archaeopteryx lithographica (Vogel-Feder) und
Pterodactylus von Solenhofen.] Neues Jahrbuch fu?r Mineralogie,
Geognosie, Geologie und Petrefakten-Kunde 1861:678?679.
Wellnhofer, P. 1993. Das siebte Exemplar von Archaeopteryx aus den
Solnhofener Schichten. Archaeopteryx 11:1?48.
BOOK REVIEW 311