Conceived and designed the experiments: DWEH HT EF MR. Performed the experiments: HT. Analyzed the data: DWEH HT EF. Contributed reagents/materials/analysis tools: HT MR. Wrote the paper: DWEH HT EF MR.
Current address: Department of Earth Sciences, University of Bristol, Bristol, United Kingdom
The authors have declared that no competing interests exist.
The ‘Solnhofen Limestone’ beds of the Southern Franconian Alb, Bavaria, southern Germany, have for centuries yielded important pterosaur specimens, most notably of the genera
The specimen was examined firsthand by all authors. Additional investigation and photography under UV light to reveal details of the bones not easily seen under normal lighting regimes was completed.
This taxon heralds from a newly explored locality that is older than the classic Solnhofen beds. While similar to
Pterosaur diversity is currently in an exponential phase of discovery
Important new pterosaur material continues to be uncovered in the Solnhofen and its surrounding beds (e.g.
Here we report on a new non-pterodactyloid pterosaur based on a complete and articulated specimen of a young juvenile. Despite a close affinity with the well-known pterosaur
Pterosauria Kaup, 1834
Breviquartossa Unwin, 2003
Rhamphorhynchidae Seeley, 1870
urn:lsid:zoobank.org:act:C309EFA2-8938-426F-9643-572225B53541.
urn:lsid:zoobank.org:act:C0C68EB9-D8A5-4C28-B517-4F14553B8119.
Specimen BSP–1993–XVIII–2 (BSP: Bayerische Staatssammlung für Paläontologie und historische Geologie, Munich, Germany) is a complete and articulated skeleton of a juvenile non-pterodactyloid pterosaur seen in ventral view.
From the Latin ‘bellus’ meaning beautiful and Brunn from the locality of the holotype specimen. This then is the beautiful one of Brunn. The species name honours Monika Rothgaenger who found the holotype.
Rhamphorhynchine pterosaur that differs from other rhamphorhynchines by the following diagnostic features: 22 or fewer teeth in total, no elongate zygopophyses or elongate chevrons in the tail, distal half of the humeral shaft straight, humerus significantly longer (1.4 times the length) of the femur, femoral head with no neck.
The specimen was found in summer 2002 during an investigation of the Brunn quarry by Monika Rothgaenger, who was at the time in charge of the privately organised scientific excavation in cooperation with the Bavarian State Collection for Palaeontology, Munich and the Solnhofen Museum, Bavaria. The specimen was subsequently prepared by freelance preparator Martin Kapitzke in Stuttgart before coming to the Solnhofen Museum in 2003. While permanently housed in the Solnhofen Museum as specimen BSP–1993–XVIII–2 (formerly curated as BSP XVIII–VFKO–A12), the material is owned by Bavarian State Collection for Palaeontology and Geology, Munich, Bavaria, Germany (BSP). See
Scale bare 1 cm.
The small village of Brunn is situated in Upper Palatinate, Eastern Bavaria, 25 km northwest of the city of Regensburg on the westernmost rim of the Southern Franconian Alb. The Brunn quarry is a small stone pit at the “Kohlstatt locality”, between the villages of Brunn and Wischenhofen, which was previously quarried for road building materials. Starting around 1990 some well-preserved fossils were discovered by collectors, and the first scientific excavations took place soon afterwards. These yielded many fossil plants and numerous invertebrate and vertebrate taxa. The Brunn quarry is now a protected site reserved for geological research only (Geological map of Bavaria 1∶25 000, sheet 6937, Laber and sheet 6837, Kallmünz).
Palaeogeographically the Kohlstatt locality is part of the Plattenkalk deposits of the small Pfraundorf-Heitzenhofen Basin
Stage | Zone | Subzone | Horizon | Localities |
Tithonian | Palmatus |
|
||
|
||||
Ciliata |
|
|||
|
||||
|
Ellenbrunn | |||
Vimineus |
|
|||
Mucronatum |
|
|||
|
Gansheim, Störzelmühle | |||
Hybonotum | Moernsheimensis |
|
||
|
|
|||
Rueppellianus |
|
|
||
|
|
|||
Riedense | unnamed |
|
||
|
|
|||
Kimmeridgian | Beckeri | Ulmense |
|
Painten, Schamhaupten, Öchselberg, Walting |
|
Nusplingen | |||
|
Nusplingen, Grosser Kirchbühl) | |||
|
||||
Setatum |
|
|||
|
Dollnstein (Torleite) | |||
|
Beilngries | |||
|
Beilngries | |||
|
||||
Subeumela |
|
|||
|
||||
|
|
|||
|
||||
Pseudomutabilis | Pseudomutabilis |
|
||
Not yet studied in detail | Wattendorf |
Based on Schweigert (2007) Traditional Solnhofen localities are in bold, Brunn is in capitals.
The speimen was described primarily under normal lighting regimes and examined with and without a light microscope and hand lens. Additional examination and photographs were then taken under UV lights by H.T.
For a general introduction to the methods used here to visualise vertebrate fossils in ultraviolet-light (UV) light see
Different filter and light combinations illuminate the bones and matrix differently providing greater clarity of some details. A selection are shown here for reference.
No specific permits were required for the described field studies.
The electronic version of this document does not represent a published work according to the International Code of Zoological Nomenclature (ICZN), and hence the nomenclatural acts contained in the electronic version are not available under that Code from the electronic edition. Therefore, a separate edition of this document was produced by a method that assures numerous identical and durable copies, and those copies were simultaneously obtainable (from the publication date noted on the first page of this article) for the purpose of providing a public and permanent scientific record, in accordance with Article 8.1 of the Code. The separate print-only edition is available on request from PLoS by sending a request to PLoS ONE, 1160 Battery Street, Suite 100, San Francisco, CA 94111, USA along with a check for $10 (to cover printing and postage) payable to “Public Library of Science”. The online version of the work is archived and available from the following digital repositories: PubMedCentral, LOCKSS.
In addition, this published work and the nomenclatural acts it contains have been registered in ZooBank in the proposed online registration system for the ICZN. The ZooBank LSIDs (Life Science Identifiers) can be resolved and the associated information viewed through any standard web browser by appending the LSID to the prefix “
The specimen is a complete and articulated skeleton of a juvenile non-pterodactyloid pterosaur seen in ventral view (see
Abbreviations as follows for this and, where appropriate, subsequent figures: cdv, caudal vertebrae; chv, chevron; co, coracoid; cp, carpus; cs, cristospine; cr, cervical rib; cv, cervical vertebrae; dr, dorsal rib; dv, dorsal vertebrae; fb, fibula; fe, femur; g, gastralium; hu, humerus; il, ilium; ish, ischium; mc, metacarpal; md, manual digit; mn, manus; pb, pubis; pd, pedal digit; ppb, prepubis; ptd, pteroid; r, ribs; rad, radius; sc, scapula; sk, skull; st, sternum; ul, ulna; wmc, wing metacarpal; wpx, wing phalanx.
Element/Anatomical section | Length (L/R) mm |
Skull | 23 (13 wide at base of skull) |
Cervical series | 19 (last cervical obscured) |
Dorsal series | 25 |
Sacral series | 4 |
Caudal series | 71 |
Sclerotic ring (left) | External diameter 6, internal diameter 3 |
Coracoid | 9/10 |
Scapula | 11/12 |
Humerus | 14/14 |
Ulna | 22/22 |
Metacarpal IV | 9/9 |
Phalanx IV-I | 27/27 |
Phalanx IV-II | 23/23 |
Phalanx IV-III | 20/21 |
Phalanx IV-IV | 23/23 (measured in straight line) |
Femur | 10/10 |
Tibia | 12/12 |
Metatarsal I | 6/6 |
Sternum | 8 (7 wide) |
The skull is especially difficult to interpret. As seen in ventral view, the mandible overlaps the palate that in turn lies over the skull roof. To add further complication, some elements have disarticulated and moved a little from their natural positions. Some elements may have been broken or distorted under compaction, and some sutures between elements are incomplete or unclear, probably due to incomplete ossification. Some of the identifications of skull and mandibular elements must therefore be regarded as tentative (
Scale bar is 5 mm.
The teeth are shaded pale grey and the non-cranial elements are in dark grey. Abbreviations as follows: ar, articular; bpt, basipterygoid; dt, dentary; fr, frontal; hy, hyoid; jg, jugal; mx, maxilla; ns, nasal; op, opsithotic; pl, palatine; pmx, premaxilla; pr, prootic; ps, parasphenoid; pt, pteryoid; qd, quadrate; qj, quadratojugal; scl, sclerotic ring; sq, squamosal.
The skull is triangular in outline in ventral view with a gentle tapering to a rounded anterior terminus (
Both jugals are seen in lateral view, though their ventral margins are obscured by the dentaries (
A large part of the skull roof can be seen to be
The palate is largely intact though elements have broken and moved (
The parasphenoid lies in the median line of the palate posterior to the orbits. It is a long, thin element that strongly tapers anteriorly to a point. The paraspenoid is broken in several places but otherwise is complete (
The mandible is preserved in articulation with the skull and the contralateral rami of the dentaries are fused anteriorly in the midline to form the symphysis (
A total of 21 teeth are visible in the skull and mandible, and thus presumably the animal had 22, assuming all teeth were paired. It is not clear however, which teeth belong to which tooth bearing skull element (of the premaxillae, maxillae and dentaries). This is likely to represent most of the original teeth as in rhamphorhynchid pterosaurs the teeth are partly directed out from the jaws, such that during dorsoventral compression of the cranium the teeth should be spread out around the jawline and be visible. Even if the teeth turned inwards, these should then be visible on top of the palate. The largest teeth are those of the anterior part of maxilla and the anterior dentary. Teeth are smaller in the premaxilla (about half the length and width of the largest teeth), and only slightly smaller that these in the posterior part of maxilla and dentary. One tooth in the prexmailla appears to underlie that at the very tip and may represent an incipient replacement tooth. If so, then the true tooth count would be 20. All teeth are simple, spike-like and appear to be sub-circular in cross-section (
Both sclerotic rings are present (
At least seven cervical vertebrae are present, (not including the atlas/axis complex which is not visible and is most likely hidden by the back of the skull) (
The unfused cervical ribs are clearly visible to each side of the column. Scale bar is 5mm.
There are approximately 17 dorsal vertebrae present. The transition from cervicals to dorsals is hidden by the coracoids making the exact number of each difficult to determine. Most of the dorsals are in their natural articulation, though some of the mid dorsal centra have separated from each other and moved a short distance laterally (
Note the displaced single centrum and the lack of fusion between centra and neural arches. Scale bar is 5 mm.
Note the disarticulation of the major elements. Thin splint-like elements lying anterior to the prepubes are probably gastralia. Scale bar is 5 mm.
At least five gastralia are present along the middle to posterior part of the dorsal vertebral series (
Scale bar is 1 cm.
Three sacrals are inferred to be present (
Thirty-eight caudals are present (including the terminal caudal which is distinguished by having a rounded posterior tip). One distal caudal is missing from the slab but a mould on the matrix shows that it was previously present. The caudals are seen in right lateral view and the neural arches appear to be dorsoventrally very short and not fused to the centra (
The scapulae and coracoids are not fused into their respective scapulocoracoid pairs and lie slightly apart from each other in each case (
Scale bar is 1 cm.
The sternum has a large cristospine that extends anteriorly and is nearly as long as the body of the sternum itself (
The humerus is straight, with no curvature to the distal part of the shaft that is seen in many non-pterodactyloid pterosaurs including small
The radius and ulna are subequal in length and appear to be similarly robust (
The elements of the carpus are slightly disarticulated (more so on the left arm) and are not fused together as in adult pterosaurs, all elements appear to be present however (
The metacarpals of digits I-III are slightly separated from each other and from the large wing metacarpal (IV) (
Individual phalanges are not labelled for clarity. Note the damage to the ventral part of the ungual of digit 3 on the right hand. Scale bar is 5 mm.
Metacarpal IV is robust and tapers strongly towards its distal end before the enlarged ginglymoid distal end (
Also visible is the fact that wing phalanx 3 has rotated along its long axis. Scale bar is 2 cm.
All the elements of the pelvis are present (
The femur is short relative to the humerus (see below). The head is offset medially from the shaft at about 90° and there is no constricted neck at the base of the femoral head (
At least two tarsals are present on each pes (two are visible on the left foot and three on the right) (
Note that on the right foot some bones are missing but impressions of them remain. The ankle elements are preserved despite their extremely small size. Scale bar is 5 mm.
Both pedes are near complete (
In addition to body size, Bennett
The orbits are very large and the skull is proportionally short and broad, as are the edentulous jaw tips with a blunt tip to the lower jaw. The texture of the bones is rough-porous and grainy-granulated seen in other juvenile pterosaurs
Measurements of the skeleton (See
Comparisons to rhamphorhynchine taxa
Taxon | Humeral length mm | Forelimb/Hindlimb | Humerus/Femur | Ulna/Tibia | Humerus/Metacarpal IV ratio |
Rhamphorhynchinae | - | 3.40–5.49 | 1.03–1.48 | 1.25–1.81 | 0.39–0.68 |
16.5 | 6.55 | 1.32 | 1.72 | 0.60 | |
15.5 | 6.15 | 1.32 | 1.72 | 0.61 | |
14.5 | 6.17 | 1.32 | 1.60 | 0.54 | |
13.5 | 6.14 | 1.23 | 1.62 | 0.63 | |
21.8 | 6.32 | 1.28 | 1.70 | 0.63 | |
19 | 6.89 | 1.19 | 1.86 | 0.53 | |
33 | 6.91 | 1.18 | 1.56 | 0.58 | |
34 | 6.72 | 1.21 | 1.45 | 0.53 | |
51 | 4.18 | 1.21 | 1.38 | 0.49 | |
61 | 4.34 | 1.22 | 1.48 | 0.48 | |
17.8 | 6.07 | 1.46 | 1.85 | 0.93 | |
46.5 | – | – | – | 0.57 | |
|
|
|
|
|
|
Data for the clade Rhamphorhynchinae taken from Unwin, 2003; various specimens of
Footnote: Institutional abbreviations for specimens listed in
Several other rhamphorhynchine taxa are known from little or incomplete material making comparisons difficult, but some clear differences are present between all described rhamphorhynchines and
Disagreements remain between taxonomists over the issue of taxonomy
Most of the apomophic characters given by Bennett
One character proposed by Bennett
The proportions of major elements and groups (
Wellnhofer
Collectively then, with the exception of the tooth count and tail morphology,
The lack of elongate pre- and postzygapophyses on the tail of
The presence of very small and often poorly ossified elements in
Finally, a loss by preparation can be positively excluded given the excellent nature of the preparation on the specimen and the fact that at least some are retained. Accidental removal of such tiny structures as the chevrons is not impossible, but as noted above, it seems unlikely that every chevron or zygopophysis could accidentally be removed or damaged without disturbing the rest of the specimen or leaving a trace on the matrix. This morphology then does represent a clear distinction for
Curved distal wing finger phalanges are known in several pterosaur specimens, both with curvature more mild, and more extreme, than seen here. For example in one specimen of
Here in
While the curvature is only gentle, this would provide a different wingshape to any other known pterosaur (life reconstruction in
Image created by Matt Van Rooijen.
The fauna and flora of the Brunn lagerstätte are different to that of the Solnhofen type Lagerstätten itself
Despite the faunal and floral differences to the Solnhofen
It was recently suggested that the extreme similarity of
The broad similarities between Brunn and the Solnhofen in terms of ecosystems and environments, give rise to the possibility that many more pterosaur specimens, and perhaps many more taxa will eventually be found at Brunn. The Solnhofen remains a very important pterosaur fauna and, given the relative lack of new taxa discovered over many years, is likely either complete or close to complete (although material perhaps representing new species remains in private hands - cf.
We thank Emma Lawlor for help measuring the specimen and in creating the figures. Laetita Adler for introducing DWEH to the specimen and providing early photos. Thanks to Colin Palmer and Mike Habib for discussions over the effects of curved wing phalanges in pterosaurs. We thank two anonymous referees for their comments which helped improve the manuscript and Leon Claessens for ushering the manuscript towards publication.