scholarly journals The first definite record of a Valanginian ichthyosaur and its implications on the evolution of post-Liassic Ichthyosauria

2018 ◽  
Author(s):  
Valentin Fischer ◽  
Arnaud Clément ◽  
Myette Guiomar ◽  
Pascal Godefroit
Keyword(s):  
Late Jurassic ◽  
Upper Jurassic ◽  
Feeding Guild ◽  
Tooth Morphology ◽  
Southern Germany ◽  
Wear Pattern ◽  
First Occurrence

A complete ichthyosaur rostrum, with 124 associated teeth, was recently discovered in Laux-Montaux locality, department of Drôme, southeastern France. The associated belemnites and ammonites indicate a late Valanginian age (Neocomites peregrinus Zone, Olcostephanus nicklesi Subzone) for this fossil, which consequently represents the first diagnostic ichthyosaur ever reported from Valanginian strata. This spec- imen also represents the first occurrence of Aegirosaurus outside the Tithonian (Upper Jurassic) lithographic limestones of Bavaria (southern Germany). Tooth morphology and wear pattern suggest that Aegirosaurus belonged to the “Pierce II/ Generalist” feeding guild, which was hitherto not represented in post-Liassic ichthyosaurs. Most Late Jurassic ichthyosaurs actually crossed the Jurassic-Cretaceous boundary.

scholarly journals On a remarkable new species of <i>Tharsis</i>, a Late Jurassic teleostean fish from southern Germany: its morphology and phylogenetic relationships

Fossil Record ◽  
2019 ◽  
Vol 22 (1) ◽  
pp. 1-23 ◽  
Author(s):  
Gloria Arratia ◽  
Hans-Peter Schultze ◽  
Helmut Tischlinger
Keyword(s):  
New Species ◽  
Late Jurassic ◽  
Strong Support ◽  
Sister Group ◽  
Common Species ◽  
Upper Jurassic ◽  
Morphological Characters ◽  
Morphological Description ◽  
Sister Group Relationship ◽  
Southern Germany

Abstract. A complete morphological description, as preservation permits, is provided for a new Late Jurassic fish species (Tharsis elleri) together with a revision and comparison of some morphological features of Tharsis dubius, one of the most common species from the Solnhofen limestone, southern Germany. An emended diagnosis of the genus Tharsis – now including two species – is presented. The new species is characterized by a combination of morphological characters, such as the presence of a complete sclerotic ring formed by two bones placed anterior and posterior to the eye, a moderately short lower jaw with quadrate-mandibular articulation below the anterior half of the orbit, caudal vertebrae with neural and haemal arches fused to their respective vertebral centrum, and parapophyses fused to their respective centrum. A phylogenetic analysis based on 198 characters and 43 taxa is performed. Following the phylogenetic hypothesis, the sister-group relationship Ascalaboidae plus more advanced teleosts stands above the node of Leptolepis coryphaenoides. Both nodes have strong support among teleosts. The results confirm the inclusion of Ascalabos, Ebertichthys and Tharsis as members of this extinct family. Tharsis elleri n. sp. (LSID urn:lsid:zoobank.org:act:6434E6F5-2DDD-48CF-A2B1-827495FE46E6, date: 13 December 2018) is so far restricted to one Upper Jurassic German locality – Wegscheid Quarry near Schernfeld, Eichstätt – whereas Tharsis dubius is known not only from Wegscheid Quarry, but also from different localities in the Upper Jurassic of Bavaria, Germany, and Cerin in France.

scholarly journals First occurrence of a gigantic pliosaurid plesiosaur in the late Jurassic (Kimmeridgian) of Mexico

2003 ◽  
Vol 174 (3) ◽  
pp. 271-278 ◽  
Author(s):  
Marie-Céline Buchy ◽  
Eberhard Frey ◽  
Wolfgang Stinnesbeck ◽  
José Guadalupe López-Oliva
Keyword(s):  
Vertebral Column ◽  
Late Jurassic ◽  
Upper Jurassic ◽  
South American ◽  
Western Tethys ◽  
Marine Reptiles ◽  
Family Level ◽  
First Occurrence ◽  
Additional Support ◽  
The University

Abstract Reinvestigation of a partial vertebral column from the Kimmeridgian La Caja Formation of Mexico, housed in the University of Linares (Mexico), and previously attributed to a dinosaur, proves to be from a very large pliosaurid plesiosaur. This specimen represents the first plesiosaur described from the Jurassic of Mexico. Its length has been estimated at 15 metres and, as a juvenile, is considered to be one of the largest Jurassic marine reptiles. The remains of this animal are here described. The morphology of the vertebral column is not diagnostic beyond family level. Large pliosaur vertebrae of a similar size are known from the Upper Jurassic of Europe, and are often referred to the genera Liopleurodon or Simolestes but these identifications are based only upon the size of the centra and have no taxonomic justification. A portion of rostrum with teeth was discovered together with the vertebral column but is unfortunately now lost. The Mexican pliosaur fills geographical and chronological gaps between western Tethys and South American pliosaurs, and is an additional support to the hypothesis of a Hispanic corridor linking at least temporarily the NW European marine province with the western South American marine (Pacific) realm during the late Jurassic.

scholarly journals An unusually diverse northern biota from the Morrison Formation (Upper Jurassic), Black Hills, Wyoming

2020 ◽  
Vol 7 ◽  
pp. 29-67
Author(s):  
John Foster ◽  
Darrin Pagnac ◽  
ReBecca Hunt-Foster
Keyword(s):  
North America ◽  
Late Jurassic ◽  
Upper Jurassic ◽  
River Channel ◽  
Black Hills ◽  
Morrison Formation ◽  
Vertebrate Fauna ◽  
Type Area ◽  
First Occurrence

The Little Houston Quarry in the Black Hills of Wyoming contains the most diverse vertebrate fauna in the Morrison Formation (Upper Jurassic) north of Como Bluff and the second-most diverse in the entire formation, after Reed’s Quarry 9. The deposit was an occasionally reactivated abandoned river channel, in interbedded green mudstone and laminated green-gray siltstone above a channel sandstone. The dinosaur material is densely distributed and is disarticulated to articulated, with several associated skeletons. The biota contains charophytes, horsetails, a possible seed fern, possible conifers, gastropods, two types of unionoid bivalves, diplostracans (“conchostracans”), a malacostracan, ray-finned fish, lungfish, a frog, salamanders, two types of turtles, rhynchocephalians, a lizard, choristoderes, two types of crocodyliforms, a pterosaur, Allosaurus and several types of small theropods including Tanycolagreus? and probable dromaeosaurids, numerous Camarasaurus and a diplodocine sauropod, a stegosaur, the neornithischian Nanosaurus, and the mammals Docodon, Amblotherium, and a multituberculate. Among these taxa, one of the unionoid bivalves, an atoposaurid crocodyliform, and the species of Amblotherium, which appear to be new and unique to the locality so far. The Docodon material may represent the first occurrence of D. apoxys outside of its type area in Colorado. Additionally, small, unusual theropod tooth types reported here may represent the first Late Jurassic occurrence of cf. Richardoestesia in North America and a possible abelisauroid, respectively.

scholarly journals New remarkable Late Jurassic teleosts from southern Germany: Ascalaboidae n. fam., its content, morphology, and phylogenetic relationships

Fossil Record ◽  
2016 ◽  
Vol 19 (1) ◽  
pp. 31-59 ◽  
Author(s):  
G. Arratia
Keyword(s):  
Late Jurassic ◽  
Sister Group ◽  
Upper Jurassic ◽  
Early Ontogeny ◽  
Sister Group Relationship ◽  
New Genus And Species ◽  
Southern Germany ◽  
New Family ◽  
Fish Taxon ◽  
Primitive Forms

Abstract. Complete morphological descriptions, as preservation permits, are provided for a new Late Jurassic fish taxon (Ebertichthys ettlingensis n. gen. et n. sp.) and a revision of some morphological features of Ascalabos voithii Graf zu Münster from the Solnhofen limestones, southern Germany. A new family, Ascalaboidae, is erected to include the two species. The new family is supported by numerous synapomorphies, e.g., maxilla with external row of small conical teeth increasing in size posteriorly, absence of gular plate, low number of vertebrae (34 to 39), deep and narrow supracleithrum – deeper than opercle, and vertebral centrum formation of caudal region including paired chordacentra (pseudo-diplospondyly) that fuse in early ontogeny forming one chordacentrum that is later surrounded by an autocentrum. A phylogenetic analysis based on 173 characters and 42 taxa was performed. Following the phylogenetic hypothesis, the sister-group relationship [Ascalabos + Ebertichthys] + more advanced teleosts stands above the node of Leptolepis coryphaenoides plus more advanced teleosts and below the node of Tharsis plus more advanced teleosts, and the new taxa are interpreted as extinct and primitive forms within Teleostei. The new genus and species is endemic and restricted to one Upper Jurassic locality – Ettling – whereas Ascalabos is known from different localities in the Solnhofen limestones, with the exception of Ettling.

First occurrence of the genus Dakosaurus (Crocodyliformes, Thalattosuchia) in the Late Jurassic of Mexico

2007 ◽  
Vol 178 (5) ◽  
pp. 391-397 ◽  
Author(s):  
Marie-Céline Buchy ◽  
Wolfgang Stinnesbeck ◽  
Eberhard Frey ◽  
Arturo H. Gonzalez Gonzalez
Keyword(s):  
Central America ◽  
Late Jurassic ◽  
Upper Jurassic ◽  
San Juan ◽  
Salt Glands ◽  
Large Space ◽  
Marine Reptiles ◽  
First Occurrence ◽  
Northeastern Mexico ◽  
The Village

Abstract The fragmentary rostrum of a thalattosuchian is described. The specimen comes from the vicinity of the village of San Juan de los Dolores, next to Los Lirios, Coahuila, northeastern Mexico. Associated ammonites allow to assign the specimen to the Kimmeridgian section (Upper Jurassic) of the La Casita Formation. Because of its massiveness, its cranial architecture and the morphology of its teeth, the specimen is referred to the genus Dakosaurus, but is too incomplete for further determination. The genus is known by few specimens from the Late Jurassic of Europe and Argentina, and was until now unknown from North and Central America. It represents a new but expected element of the assemblage of marine reptiles populating the Mexican Gulf during the Late Jurassic. The specimen is one of the few members of the group preserving in 3 dimensions and visible, the preorbital portion of the rostrum, and especially of the nasopharyngeal canal; it confirms the existence of a large space possibly housing salt glands rostral to the orbits.

scholarly journals Ostracods from the Upper Jurassic (Oxfordian-Tithonian) of southern Germany

2000 ◽  
Vol 19 (2) ◽  
pp. 97-112 ◽  
Author(s):  
U. Schudack ◽  
M. E. Schudack
Keyword(s):  
New Species ◽  
Late Jurassic ◽  
Upper Jurassic ◽  
Systematic Investigation ◽  
Southern Germany

Abstract. At present the ostracod faunas from the Upper Jurassic of southern Germany are incompletely known due to the absence of detailed studies. This preliminary systematic investigation has yielded 46 species from 25 genera, of which 23 species are left in open nomenclature, while 4 are new species: Bythoceratina (Praebythoceratina) danuvensis, Nemoceratina (Pariceratina) urlichsi, Pokornyopsis punctata and Quasihermanites spiralus. Diversity increases through the late Jurassic with 16 species in the Oxfordian, 19 species in the Kimmeridgian, and 23 species in the Tithonian. Endemism is lowest in the Oxfordian, while highest in the Kimmeridgian.

scholarly journals The taphonomy of dinosaurs from the Upper Jurassic of Tendaguru (Tanzania) based on field sketches of the German tendaguru expedition (1909–1913)

Fossil Record ◽  
1999 ◽  
Vol 2 (1) ◽  
pp. 25-61 ◽  
Author(s):  
W.-D. Heinrich
Keyword(s):  
Old Age ◽  
Late Jurassic ◽  
Depositional Environment ◽  
Upper Jurassic ◽  
Skeletal Remains ◽  
Time Span ◽  
Post Mortem ◽  
Seasonal Drought ◽  
Long Time

Tendaguru is one of the most important dinosaur localities in Africa. The Tendaguru Beds have produced a diverse Late Jurassic (Kimmeridgian to Tithonian) dinosaur assemblage, including sauropods (<i>Brachiosaurus, Barosaurus, Dicraeosaurus, Janenschia</i>), theropods (e.g., <i>Elaphrosaurus, Ceratosaurus, Allosaurus</i>), and ornithischians (<i>Kentrosaurus, Dryosaurus</i>). Contrary to the well studied skeletal anatomy of the Tendaguru dinosaurs, the available taphonomic information is rather limited, and a generally accepted taphonomic model has not yet been established. Assessment of unpublished excavation sketches by the German Tendaguru expedition (1909–1913) document bone assemblages of sauropod and ornithischian dinosaurs from the Middle Saurian Bed, Upper Saurian Bed, and the Transitional Sands above the <i>Trigonia smeei</i> Bed, and shed some light on the taphonomy of the Tendaguru dinosaurs. Stages of disarticulation range from incomplete skeletons to solitary bones, and strongly argue for carcass decay and post-mortem transport prior to burial. The sauropod bone accumulations are dominated by adult individuals, and juveniles are rare or missing. The occurrence of bones in different superimposed dinosaur-bearing horizons indicates that skeletal remains were accumulated over a long time span during the Late Jurassic, and the majority of the bone accumulations are probably attritional. These accumulations are likely to have resulted from long-term bone imput due to normal mortality events caused by starvation, seasonal drought, disease, old age and weakness. The depositional environment of the Middle and Upper Saurian Bed was mainly limnic to brackish in origin, while the palaeoenvironment of the Transitional Sands was marginal marine. <br><br> Tendaguru zählt zu den bedeutendsten Dinosaurier-Lagerstätten Afrikas. Aus den Tendaguru-Schichten sind zahlreiche Skelettreste von Sauropoden (<i>Brachiosaurus, Barosaurus, Dicraeosaurus, Janenschia</i>), Theropoden (z.B. <i>Elaphrosaurus, Ceratosaurus, Allosaurus</i>) und Ornithischiern (<i>Kentrosaurus, Dryosaurus</i>) geborgen worden. Sie stammen aus der späten Jura-Zeit (Kimmeridge — Tithon). Während der Skelettbau der Tendagurusaurier gut untersucht ist, wirft die Taphonomie des Sauriervorkommens von Tendaguru noch immer Fragen auf. Unklar ist bislang, wie die enormen Anreicherungen von Dinosaurierknochen in den Tendaguru-Schichten zustandekamen. Unveröffentlichte Grabungsskizzen der Deutschen Tendaguru Expedition (1909–1913) erweitern unsere Kenntnisse über die Taphonomie der Tendagurusaurier. In den ausgewerteten Grabungsskizzen sind Knochenansammlungen von Sauropoden und Ornithischiern aus dem Mittleren und Oberen Sauriermergel sowie aus den Übergangsschichten über der <i>Trigonia smeei</i>-Schicht dokumentiert. Die Lage und der Erhaltungszustand der Funde lassen auf erheblichen Zerfall der Kadaver und post-mortalen Transport von Skelettelementen vor der Einbettung schließen. Das Vorkommen von Saurierknochen in mehreren übereinanderliegenden Profilabschnitten der Tendaguru-Schichten zeigt, daß Skelettreste während der späten Jura-Zeit über einen längeren Zeitraum hinweg akkumuliert wurden. Die Ansammlungen von Skelettresten gehen wahrscheinlich auf „normale” Sterbe-Ereignisse zurück, wie z. B. Verhungern, Verdursten, Kankheit, Altersschwäche und jahreszeitliche Dürre. Als Ablagerungsraum der Mittleren und Oberen Saurierschicht kommt ein küstennaher limnischer, zeitweise wohl auch brackischer Küstenstreifen in Betracht. Die knochenführenden Übergangsschichten unter- und oberhalb der Saurierschichten sind randlich marine Ablagerungen. <br><br> doi:<a href="http://dx.doi.org/10.1002/mmng.1999.4860020102" target="_blank">10.1002/mmng.1999.4860020102</a>

scholarly journals Detrital zircon geochronology and provenance of the Middle to Late Jurassic Paradox Basin and Central Colorado trough: Paleogeographic implications for southwestern Laurentia

Geosphere ◽  
2021 ◽  
Author(s):  
John I. Ejembi ◽  
Sally L. Potter-McIntyre ◽  
Glenn R. Sharman ◽  
Tyson M. Smith ◽  
Joel E. Saylor ◽  
...  
Keyword(s):  
Sediment Transport ◽  
Detrital Zircon ◽  
Late Jurassic ◽  
Upper Jurassic ◽  
Morrison Formation ◽  
Detrital Zircon Geochronology ◽  
Sediment Dispersal ◽  
Paradox Basin ◽  
Southern Oklahoma ◽  
Trace Elemental

Middle to Upper Jurassic strata in the Paradox Basin and Central Colorado trough (CCT; south­western United States) record a pronounced change in sediment dispersal from dominantly aeolian deposition with an Appalachian source (Entrada Sandstone) to dominantly fluvial deposi­tion with a source in the Mogollon and/or Sevier orogenic highlands (Salt Wash Member of the Morrison Formation). An enigmatic abundance of Cambrian (ca. 527–519 Ma) grains at this prove­nance transition in the CCT at Escalante Canyon, Colorado, was recently suggested to reflect a local sediment source from the Ancestral Front Range, despite previous interpretations that local base­ment uplifts were largely buried by Middle to Late Jurassic time. This study aims to delineate spatial and tem­poral patterns in provenance of these Jurassic sandstones containing Cambrian grains within the Paradox Basin and CCT using sandstone petrog­raphy, detrital zircon U-Pb geochronology, and detrital zircon trace elemental and rare-earth ele­mental (REE) geochemistry. We report 7887 new U-Pb detrital zircon analyses from 31 sandstone samples collected within seven transects in west­ern Colorado and eastern Utah. Three clusters of zircon ages are consistently present (1.53–1.3 Ga, 1.3–0.9 Ga, and 500–300 Ma) that are interpreted to reflect sources associated with the Appalachian orogen in southeastern Laurentia (mid-continent, Grenville, Appalachian, and peri-Gondwanan terranes). Ca. 540–500 Ma zircon grains are anom­alously abundant locally in the uppermost Entrada Sandstone and Wanakah Formation but are either lacking or present in small fractions in the overlying Salt Wash and Tidwell Members of the Morrison Formation. A comparison of zircon REE geochem­istry between Cambrian detrital zircon and igneous zircon from potential sources shows that these 540–500 Ma detrital zircon are primarily magmatic. Although variability in both detrital and igneous REE concentrations precludes definitive identifica­tion of provenance, several considerations suggest that distal sources from the Cambrian granitic and rhyolitic provinces of the Southern Oklahoma aulacogen is also likely, in addition to a proximal source identified in the McClure Mountain syenite of the Wet Mountains, Colorado. The abundance of Cambrian grains in samples from the central CCT, particularly in the Entrada Sandstone and Wana­kah Formation, suggests northwesterly sediment transport within the CCT, with sediment sourced from Ancestral Rocky Mountains uplifts of the southern Wet Mountains and/or Amarillo-Wichita Mountains in southwestern Oklahoma. The lack of Cambrian grains within the Paradox Basin sug­gests that the Uncompahgre uplift (southwestern Colorado) acted as a barrier to sediment transport from the CCT.

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