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© 2006 Nature Publishing Group
A new carnivorous dinosaur from the Late Jurassic
Solnhofen archipelago
Ursula B. Go
¨
hlich
1
& Luis M. Chiappe
2
Small Late Jurassic theropod dinosaurs are rare worldwide. In
Europe these carnivorous dinosaurs are represented primarily by
only two skeletons of Compsognathus
1,2
, neither of which is well
preserved. Here we describe a small new theropod dinosaur from
the Late Jurassic period of Schamhaupten in southern Germany
3,4
.
Being exquisitely preserved and complete from the snout to the
distal third of the tail, the new fossi l is the b est-pre served
predatory, non-avian dinosaur in Europe. It possesses a suite of
characters that support its identification as a basal coelurosaur.
A cladistic analysis indicates that the new taxon is closer to
maniraptorans than to tyrannosauroids, grouping it with taxa
often considered to be compsognathids. Large portions of integu-
ment are preserved along its tail. The absence of feathers or
feather-like structures in a fossil phylogenetically nested within
feathered theropods
5,6
indicates that the evolution of these integu-
mentar y structures might be more complex than prev iously
thought.
The new Schamhaupten fossil is the second non-avian theropod
found in the laminated limestones of the Late Jurassic Solnhofen
reef archipelago of Bavaria
7
, after the discovery of the celebrated
Compsognathus nearly 150 years ago. Biostratigraphic studies of the
Schamhaupten limestones indicate that they are 151–152 million
years old
3,4,8
, and are therefore slightly older than those containing
Compsognathus and the famous bird Archaeopteryx.
Dinosauria Owen, 1842
Theropoda Marsh, 1881C
Tetanurae Gauthier, 1986
Coelurosauria Huene, 1914
Compsognathidae Marsh, 1882
Juravenator starki gen. et sp. nov.
Etymology. Jura, referring to the Bavarian Jura mountains; plus
venator (Latin), a hunter. The species name, starki, honours the
family Stark, owner of the Quarry Stark.
Holotype. JME Sch 200 (Jura-Museum Eichsta
¨
tt), a nearly complete
and articulated skeleton missing only the distal third of its tail (Fig. 1).
The strong scarring and pitting of the bone surface
9
, the lack of fusion
between sacral vertebrae, and the presence of open neurocentral
sutures
10
demonstrate that JME Sch 200 is a juvenile.
Horizon and locality. Silicified, laminated limestone, Late Jurassic,
Upper Malm, Late Kimmeridgian, Malm Epsilon 2 (setatum-
subzone), Quarry Stark, west of Schamhaupten, Southern Franconian
Alb, Bavaria, Germany (see Supplementary Information).
Diagnosis. Small basal coelurosaur (preserved length 65 cm; esti-
mated total length 75–80 cm; see Supplementary Information for
measurements) with a small number (eight) of maxillary teeth, no
premaxillary–maxillary diastema, posterior serrations on premaxil-
lary teeth, concave rostral margin of the jugal process of the
postorbital, relatively long scapula with narrowest portion at neck,
and proportionally short feet. Juravenator starki may also be diag-
nosed by the presence of an antorbital fenestra subequal in length to
the orbit and by an abbreviated deltopectoral crest of the humerus,
although these features may be related to the early ontogenetic age
of the holotype. In addition, Juravenator is unique among basal
coelurosaurs in having proximally high manual claws that taper
abruptly at midpoint, a ventrally notched premaxillary–maxillary
contact, and bow-like zygapophyses in mid-caudal vertebrae; these
features are interpreted as autapomorphies.
Description and comparisons. The skull of JME Sch 200 is propor-
tionally large (Fig. 1). It has a moderately long rostrum, elliptical
external nares bordered by the premaxilla and nasal, a big antorbital
fossa largely perforated by an antorbital fenestra and a small
maxillary fenestra, round orbits, a flat cranial roof, and teeth lacking
anterior serrations (Fig. 2). The premaxilla bears three, perhaps
four, teeth
—
the penultimate one posteriorly serrated (Fig. 1). The
maxillary teeth are more recurved than the premaxillary ones. The
lacrimal has the shape of an inverted ‘L’. The jugal is slender with a
well-developed postorbital ramus and a tapering subtemporal ramus
that ends shortly behind the base of the latter. The frontal is large and
it participates extensively of the supratemporal fenestra. The parietal
is one-third to one-quarter the length of the frontal. The frontal
ramus of the T-shaped postorbital is slightly longer than the
squamosal ramus and shorter than the jugal ramus. The lower jaw
of Juravenator lacks a mandibular foramen, as in the compsog-
nathids
11
Compsognathus
1
, Sinosauropteryx
12
, Huaxiagnathus
13
and
Scipionyx
14
and other basal coelurosaurs such as tyrannosauroids,
and its teeth
—
probably not more than 11
—
extend caudally to nearly
the end of the upper dentition.
There are eight to ten cervical vertebrae. These have short and
low neural spines and, as in compsognathids
1,12,13
, extremely long,
hair-like ribs (Fig. 1). The trunk is composed of 13 dorsal vertebrae
with distally expanded neural spines, another synapomorphy of
compsognathids
11–13,15
. The tail is extremely long
—
comparisons
with Sinosauropteryx indicate that the 44 caudal vertebrae preserved
in JME Sch 200 represent about two-thirds of the complete tail. Such
an elongated tail is comparable to the tail of Sinosauropteryx and
longer than in most other theropods
16
. The caudal centra are
elongated and very similar throughout the tail. Their length remains
more or less constant until the 17th caudal, when the length of the
centra starts increasing. The transition point is around the 14th to
15th vertebra. The short zygapophyses of the middle caudals have a
uniquely hooked morphology (Fig. 1). The chevrons are elongate and
rod-like shaped; these bones decrease in length gradually towards the
distal end of the tail.
The scapula is slender and elongate (its length is about ten times its
width at mid-shaft and 80% of the length of the femur). This bone
has a prominent and subtriangular acromion and a scapular blade
LETTERS
1
Department for Geo- and Environmental Sciences, Section Paleontology, University of Munich, Richard-Wagner-Strasse 10, D-80333 Munich, Germany.
2
The Dinosaur Institute,
Natural History Museum of Los Angeles County, 900 Exposition Boulevard, Los Angeles, California 90007, USA.
Vol 440|16 March 2006|doi:10.1038/nature04579
329
© 2006 Nature Publishing Group
that gradually expands towards its tip. The glenoid is rimmed and
directed caudally. The forelimb is 50% of the length of the hindlimb
(measured along their longest digit and including their correspond-
ing claws)
—
Juravenator has the longest forelimb among compsog-
nathids. The deltopectoral crest of the humerus is proximodistally
very short and triangular in shape. The radius and ulna are straight
and about two-thirds the length of the humerus. Metacarpal I is
about 40% of the length of metacarpal II but of about the same width.
Metacarpal III is about half the width of metacarpal II and 75% of its
length. The hand of Juravenator carries three robust and clawed digits
(Fig. 1) with two (I), three (II) and four (III) phalanges. Digit I is the
shortest and digit II the longest. The pelvis consists of a low and
straight ilium with rounded and squared-off anterior and posterior
ends, respectively. The other elements of the pelvis are of difficult
interpretation. The hindlimbs are robust. The femur is 10% shorter
than the tibia, which is similarly shorter than the foot (metatarsal III
and digit including claw). Metatarsal III is the longest, followed by
metatarsals IVand II. Likewise, pedal digit III is the longest, followed
by digits IV, II and I; the phalangeal formula of these digits is 2-3-4-5.
Soft tissue is preserved along the tibiae, and particularly between
the 8th and the 22nd caudal vertebrae, where it defines the outline of
the tail. The latter section allows observation of the skin surface and
other soft parts (Fig. 3). The integument of Juravenator is formed of
uniformly sized, smooth tubercles (about 15 tubercles per 25 mm
2
of preserved tissue) similar in appearance to the small, conical and
non-imbricated tubercles of many other non-avian dinosaurs
17,18
.An
array of feathers has been discovered among non-avian coeluro-
saurs
6
. However, the absence of either feathers or skin follicles
associated with the preserved integument of Juravenator indicates
that at least the central portion of the tail of this coelurosaur was
devoid of plumage. The remaining soft tissue is represented by a
series of fibres ventral to the haemal arches of the 10th to 14th caudals
and parallel to the axis of the tail. These fibres probably represent
tendons of the hypaxial musculature and ligaments of the tail
19
,as
interpreted for similar soft parts associated with the skeleton of
Scipionyx
14
, although they could also correspond to bundles of
subcutaneous collagen fibres
20
.
A cladistic analysis of 35 theropod taxa (Supplementary Infor-
mation) clusters Juravenator with a diversity of other basal, small-
bodied coelurosaurs of Late Jurassic to Early Cretaceous age. When the
analysis is conducted with the exclusion of largely incomplete taxa,
Juravenator nests together with compsognathids such as Compsog-
nathus, Sinosauropteryx and Huaxiagnathus (Fig. 4). This condensed
analysis recovers a monophyletic Compsognathidae and supports the
placement of Juravenator within this clade.
The discovery of feathery integumentary coverings in a variety
of coelurosaurs (for example, tyrannosauroids, compsognathids,
therizinosauroids, oviraptorosaurs, alvarezsaurids and dromaeo-
saurids) has cemented the notion that feathers are a synapomorphy
of this entire clade
5,6
. Thus, the absence of feathers in Juravenator,a
Figure 1 | Holotype of Juravenator starki. a, Specimen photographed under
normal light. b, The presence of ‘hair-like’ cervical ribs (inset 1) is
synapomorphic of Compsognathidae. The proximally high manual claws
that taper abruptly at their midpoint (inset 2) and bow-like zygapophyses of
mid-caudal vertebrae (inset 3) are regarded as autapomorphies of
Juravenator starki. The serrated premaxillary teeth (inset 4) also distinguish
this taxon from most other basal coelurosaurs. Abbreviations: ca, calcaneus;
co, coracoid; cv, cervical vertebrae; dv, dorsal vertebrae; fe, femur; fi, fibula;
ha, haemal arches; hu, humerus; il, ilium; mI, metacarpal I; mII,
metacarpal II; ra, radius; sc, scapula; st, soft tissue; ti, tibia; ul, ulna; I–IV,
pedal digits I–IV; V, metatarsal V.
LETTERS NATURE|Vol 440|16 March 2006
330
© 2006 Nature Publishing Group
Figure 2 | Skull and mandible of Juravenator starki. a, Specimen
photographed under ultraviolet light. b, As reconstructed (shaded areas
show missing portions). Abbreviations: an, angular; aofe, antorbital
fenestra; d, dentary; en, external naris; f, frontal; itfe, infratemporal fenestra;
j, jugal; l, lacrimal; m, maxilla; mfe, maxillary fenestra; n, nasal; or, orbit; p,
parietal; pm, premaxilla; po, postorbital; qj, quadratojugal; sq, squamosal;
sa, surangular.
Figure 3 | Integument of Juravenator starki. a, Specimen photographed under ultraviolet light. b, Specimen photographed under normal light.
Abbreviations: c9, c11 and c13, caudal vertebrae 9, 11 and 13.
NATURE|Vol 440|16 March 2006 LETTERS
331
© 2006 Nature Publishing Group
taxon otherwise nested within feathered coelurosaurs, is noteworthy
(Fig. 4). The extent to which feathers covered the body of these
non-avian dinosaurs is not well known for some taxa (for example,
the tyrannosauroid Dilong
21
, the therizinosauroid Beipiaosaurus
22
,
and the alvarezsaurid Shuvuuia
6,23
) but complete specimens of
Sinosauropteryx
12,16
, the oviraptorosaur Caudipteryx
23
, and several
dromaeosaurids
24–26
indicate that the body of these animals was for
the most part feathered. The fact that Juravenator lacks any evidence
of feathers in portions of integument otherwise feathered in these
coelurosaurs indicates that these animals may have differed greatly in
the extension of their feathery covering. However, the role of
ontogeny and seasonality in the development of the plumage of
these dinosaurs remains uncertain, and the possibility cannot be
ruled out that feathers evolved more than once or became lost in taxa
such as Juravenator (Fig. 4).
The exquisitely preserved skeleton of Juravenator starki is the most
complete non-avian theropod so far discovered in Europe, adding to
the diversity of dinosaurs from this continent and in particular to the
meagre record of Late Jurassic small theropods
27
. Its discovery sheds
light on a poorly known segment of coelurosaur history and indicates
that the evolution of feathers in theropods might have been more
complex than previously envisaged.
Received 1 September 2005; accepted 10 January 2006.
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Supplementary Information is linked to the online version of the paper at
www.nature.com/nature.
Acknowledgements We thank H. Weiss and K.-D. Weiss for discovery of the
specimen, P. Vo
¨
lkl for its preparation, H. Tischlinger and G. Janssen for
photography, M. Ko
¨
lbl-Ebert and F. Stark for access to the specimen, and E. Frey,
D. Goujet, S. Hwang, R. Leinfelder, O. Rauhut, M. Ro
¨
per, G. Viohl, P. Wellnhofer
and W. Werner for providing access to specimens, for logistics, and/or for
discussions. This research was made possible by the Humboldt Foundation, and
was also supported by the Jurassic Foundation, European Commission’s
Research Infrastructure Action-Synthesys Program, Antorchas Foundation,
Bavarian State Collection for Paleontology and Geology, Department for Geo-
and Environmental Sciences (Munich University), DFG, Jura Museum, and
Natural History Museum of Los Angeles County.
Author Information Reprints and permissions information is available at
npg.nature.com/reprintsandpermissions. The authors declare no competing
financial interests. Correspondence and requests for materials should be
addressed to L.M.C. (chiappe@nhm.org).
Figure 4 | Strict consensus cladogram. The eight most parsimonious trees
(length 497, consistency index 0.45, retention index 0.65) for 28 theropod
taxa, including Juravenator starki and 189 variables, are shown (see
Supplementary Information). In spite of lacking feathers in the preserved
integumentary portions, Juravenator starki is grouped together with
coelurosaur clades known for having feathery coverings
6
. Plumulaceous
and/or pennaceous feathers have been discovered in taxa assigned to
Tyrannosauroidea (namely Dilong
21
; in this cladogram, tyrannosauroids are
represented by the more advanced Tyrannosaurus and Albertosaurus),
Compsognathidae (namely Sinosauropteryx
12,16
), Alvarezsauridae (namely
Shuvuuia
23
), Oviraptorosauria (namely Caudipteryx
24
), Dromaeosauridae
(namely Microraptor
25
and Sinornithosaurus
26
) and Aves (namely
Archaeopteryx and Confuciusornis)
28
.
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