The Paleobotanical Changes Across the Jurassic/Cretaceous Boundary in India

Integrated palaeobotanical and palynological analysis of subsurface Gondwana sedimentary succession (Jurassic–Cretaceous) in Jangareddygudem area, Chintalapudi Sub-basin, South India: Stratigraphical and phytogeographical implications

Authors:

Jha et al

Abstract:

Here we present an integrated palaeobotanical and palynological analysis of sub-surface terrestrial deposits of Jangareddygudem area, Chintalapudi Sub-basin, Godavari Graben, India. Plant megafossil impressions and palynomorphs were recovered in the bore core MJR-11 from Jangareddygudem area. Plant megafossils impressions: Equisetites sp., Ptilophyllum acutifolium, Pachypteris indica, Elatocladus jabalpurensis, Pagiophyllum gollapallensis, and Ptilophyllum cutchense are recorded at different depths in the bore core MJR-11. Palynological investigations carried out in these megafossil bearing beds reveal the presence of Coptospora sp., Ceratosporites equalis, Appendicisporites erdtmanii, Biretisporites spectabilis, Cicatricosisporites hughesii, Cicatricosisporites sp., Concavissimisporites sp., Contignisporites cooksoniae, C. fornicatus, C. glebulentus, C. multimuratus, C. psilatus, Converrucosisporites sp., Gleicheniidites sp., Klukisporites scaberis, Plicifera delicata, Balmeiopsis limbatus, Araucariacites australis, A. cooksonii, Callialasporites dampieri, C. monoalasporus, C. segmentatus, C. turbatus, Dacrycarpites australiensis, Podocarpidites ellipticus, Podosporites variabilis, Crybelosporites stylosus, and Foraminisporis wonthaggiensis. Very rare occurrence of monocolpate, tetracolpate and tricolpate pollen is also recorded. Both plant mega- and microfloral evidences indicate Late Jurrassic–Early Cretaceous (Tithonian–Valanginian) age for these sediments. A comparative study of present mega and microfossil assemblages with known megafloral and microfloral assemblage from the Upper Gondwana sediments of Godavari and other Indian basins has also been attempted. The floral assemblage clearly indicates the presence of Gangapur sediments in Jangareddygudem area.

Similarity of the Antarctic palynofloras with those known from Godavari and other basins on the east coast of India confirms continental reconstructions that show Lambert Graben of East Antarctica to have been contiguous with eastern India prior to Gondwana break-up. The non-marine character of the palynomorphs suggests that marine conditions in this region of the Godavari Graben did not develop until at least early Early Cretaceous time.

Dryolestidan Cladotherian Paurodon valens was a Tithonian Jurassic Golden Mole Parallel

Ontogeny and taxonomy of Paurodon valens (Mammalia, Cladotheria) from the Upper Jurassic Morrison Formation of USA. (pdf)

Authors:

Averianov et al

Abstract:

Several basal cladotherian taxa previously referred to the “Paurodontidae” (Dryolestida) from the Upper Jurassic Morrison Formation of Wyoming, U.S.A. represent ontogenetic and individual variation of one single taxon, Paurodon valens Marsh, 1887 (=Archaeotrigon brevimaxillus Simpson, 1927, syn. n.; = Pelicopsis dubius Simpson, 1927, syn. n.; = Archaeotrigon distagmus Simpson, 1929, syn. n.; = Araeodon intermissus Simpson, 1937, syn. n.; = Foxraptor atrox Bakker et Carpenter, 1990, syn. n.). P. valens is characterized by prolonged dental replacement, including late eruption of m4 (and m5 as individual variation) and a time gap between shedding of dp2 and eruption of p2, which can be lost in aged individuals. By a shortened dentary and mandibular symphysis, two-three simple premolariform teeth, and four molariform teeth with tall trigonid and small talonid, P. valens is strinkingly similar to the modern golden moles (Chrysochloridae), particularly to Amblysomus hottentotus. This similarity suggests that P. valens was specialized on consuming earth worms in contrast to a more insectivorous diet characteristic for other dryolestidans.

Chilesaurus diegosuarezi is From the Tithonian Jurassic

Tithonian age of dinosaur fossils in central Patagonian, Chile: U–Pb SHRIMP geochronology

Authors:

Suárez et al

Abstract:

Three Tithonian concordant U–Pb SHRIMP zircon ages of 148.7 ± 1.4, 147.9 ± 1.5 and 147.0 ± 1.0 from tuffs intercalated in a clastic sedimentary succession with exceptional dinosaur bones including the new taxon Chilesaurus diegosuarezi gen. et sp. nov. exposed in central Chilean Patagonia (ca. 46°30′S) are reported herein. The fossiliferous beds accumulated in a synvolcanic fan delta reaching a shallow marine basin as indicated by glauconite present in some of the beds, and coeval with the beginning of the transgression of the Aysén Basin.

An Exceptionally Complete Stegosaurus From Tithonian Jurassic Wyoming

The Postcranial Skeleton of an Exceptionally Complete Individual of the Plated Dinosaur Stegosaurus stenops (Dinosauria: Thyreophora) from the Upper Jurassic Morrison Formation of Wyoming, U.S.A.

Authors:

Maidment et al

Abstract:

Although Stegosaurus is one of the most iconic dinosaurs, well-preserved fossils are rare and as a consequence there is still much that remains unknown about the taxon. A new, exceptionally complete individual affords the opportunity to describe the anatomy of Stegosaurus in detail for the first time in over a century, and enables additional comparisons with other stegosaurian dinosaurs. The new specimen is from the Red Canyon Ranch Quarry, near Shell Wyoming, and appears to have been so well preserved because it was buried rapidly in a pond or body of standing water immediately after death. The quarry is probably located in the middle part of the Morrison Formation, which is believed to be Tithonian in age in this area. The specimen is referable to Stegosaurus stenops based on the possession of an edentulous anterior portion of the dentary and elevated postzygapophyses on the cervical vertebrae. New information provided by the specimen concerns the morphology of the vertebrae, the iliosacral block and dermal armor. Several aspects of its morphology indicate the individual was not fully skeletally mature at the time of death, corroborating a previous histological study.

Chilesaurus diegosuarezi: A Bizarre new Herbivorous Theropod From Tithonian Jurassic Chile

An enigmatic plant-eating theropod from the Late Jurassic period of Chile

Authors:

Novas et al

Abstract:

Theropod dinosaurs were the dominant predators in most Mesozoic era terrestrial ecosystems. Early theropod evolution is currently interpreted as the diversification of various carnivorous and cursorial taxa, whereas the acquisition of herbivorism, together with the secondary loss of cursorial adaptations, occurred much later among advanced coelurosaurian theropods. new, bizarre herbivorous basal tetanuran from the Upper Jurassic of Chile challenges this conception. The new dinosaur was discovered at Aysén, a fossil locality in the Upper Jurassic Toqui Formation of southern Chile (General Carrera Lake). The site yielded abundant and exquisitely preserved three-dimensional skeletons of small archosaurs. Several articulated individuals of Chilesaurus at different ontogenetic stages have been collected, as well as less abundant basal crocodyliforms, and fragmentary remains of sauropod dinosaurs (diplodocids and titanosaurians).

No word whether it preferred red or green.   Obviously it was a Hatched variety.

Purranisaurus potens: a Very Strange Metriorhynchid Thalattosaur From Tithonian Jurassic/Berriasian Cretaceous Patagonia

Purranisaurus potens Rusconi, an enigmatic metriorhynchid from the Late Jurassic–Early Cretaceous of the Neuquén Basin

Authors:

Herrera et al

Abstract:

The Tithonian record from northwestern Patagonia (Neuquén Basin) documents a complete succession of lower, middle, and late Tithonian marine reptiles. From the late Tithonian–early Berriasian of Patagonia, three marine crocodyliforms have been recorded: Dakosaurus andiniensis, Cricosaurus araucanensis, and Purranisaurus potens. Although P. potens includes the first metriorhynchid skull described from Patagonia, no detailed description and/or illustrations have been published. Since the mid-20th century, several authors have discussed the validity of P. potens. Recent preparation of the type material allowed a detailed description as well as exploration of its phylogenetic relationships. We consider P. potens as a valid taxon characterized by a unique combination of characters, such as medial and posterolateral processes of the frontal forming an angle of 60°; supratemporal fossae reaching the minimum interorbital distance, with the dorsal margin of the supratemporal arch being slightly concave in lateral view; thin bony lamina projecting from the lateral and medial alveolar margins of the maxilla; occipital surface ventral to occipital condyle parallel to transverse plane of skull; well-developed crest that extends along the entire height of the supraoccipital; and orbital process of the quadrate very conspicuous and acute, horizontal, and without bony attachment. Phylogenetic analysis recovers P. potens as deeply nested within Geosaurini and, contrary to previous proposals, not closely related to ‘Metriorhynchus’ casamiquelai and ‘M.’ westermanni. Internal relationships within Geosaurini are unresolved. Purranisaurus, as a monotypic genus, is restricted to the late Tithonian–early Berriasian.

Three Oldest Known Snake Fossils Found From Jurassic Bathonian Jurassic Britain, Kimmeridgian Jurassic Portugal

Fossilized remains of four ancient snakes have been dated between 140 and 167 million years old - nearly 70 million years older than the previous record of ancient snake fossils - and are changing the way we think about the origins of snakes, and how and when it happened. The findings have been published in the prestigious peer-reviewed journal Nature Communications.

"The study explores the idea that evolution within the group called 'snakes' is much more complex than previously thought," says lead author and professor Michael Caldwell in the Faculty of Science at the University of Alberta. "Importantly, there is now a significant knowledge gap to be bridged by future research as no fossils snakes are known from between 140 to 100 million years ago."

The oldest known snake, from Southern England, near Kirtlington, Eophis underwoodi, is known only from very fragmentary remains and was a small individual, though it is hard to say how old it was at the time it died. The largest snake, Portugalophis lignites, from coal deposits in Portugal, near Guimarota, was a much bigger individual at nearly a meter or more in length. Several of these ancient snakes (Eophis, Portugalophis and Parviraptor) were living in swampy coastal areas on large island chains in western parts of ancient Europe, while the North American species, Diablophis gilmorei, is found in river deposits from some distance inland in Western Colorado.

This new study makes it clear that the sudden appearance of snakes, some 100 million years ago, reflects a gap in the fossil record, not an explosive radiation of early snakes. From 167 to 100 million years ago, some 70 million years, snakes were radiating and evolving towards the elongate, limb-reduced body plan characterizing the now well known, ~100-90 million year old, marine snakes from the West Bank, Lebanon, and Argentina, that still possess small but well developed rear limbs. As is always the case, the distribution of these newer oldest snakes, and the anatomy of the skull and skeletal elements, makes it clear that even older snake fossils are waiting to be found.

"Based on the new evidence and through comparison to living legless lizards that are not snakes," explains Caldwell, "the paper explores the novel idea that the evolution of the characteristic snake skull and its parts appeared long before snakes lost their legs."

link.

paper link.

Fosterovenator churei & the Cryptic Theropod PaleoDiversity of the Tithonian Jurassic Morrison Formation

New data on small theropod dinosaurs from the Upper Jurassic Morrison Formation of Como Bluff, Wyoming, USA

Author:

Dalman

Abstract:

In 1879, Othniel C. Marsh and Arthur Lakes collected in the Upper Jurassic Morrison Formation Quarry 12 at Como Bluff, Wyoming, USA, several isolated axial and appendicular skeletal elements of small theropod dinosaurs. Since the discovery the specimens remained unnoticed for over a century. The skeletal remains of small theropods are rare at Como Bluff and throughout the Morrison Formation. Their bones are delicately constructed, so they are not as well-preserved as the bones of large-bodied theropods. The bones of small theropods described here were found mixed with isolated crocodile teeth and turtle shells. Comparison of the skeletal materials with other known theropods from the Morrison Formation reveals that some of the bones belong to a very small juvenile Allosaurus fragilis and Torvosaurus tanneri and also to a new ceratosaur taxon, here named Fosterovenator churei, whereas the other bones represent previously unidentified juvenile taxa of basal tetanuran and coelurid theropods. The discovery and description of these fossil materials is significant because they provide important information about the Upper Jurassic terrestrial fauna of Quarry 12, Como Bluff, Wyoming. The presence of previously unidentified theropod taxa in the Morrison Formation indicates that the diversity of basal tetanuran and coelurid theropods may have been much greater than previously expected. Although the fossil material here described is largely fragmentary, it is tenable that theropods of different clades co-existed in the same ecosystems at the same time and most likely competed for the same food sources.

Paleosol Analysis Shows Tithonian Jurassic PaleoClimate of North America was Very Varied

The climate 150 million years ago of a large swath of the western United States was more complex than previously known, according to new research from Southern Methodist University, Dallas.

It's been thought that the climate during the Jurassic was fairly dry in New Mexico, then gradually transitioned to a wetter climate northward to Montana.

But based on new evidence, the theory of a gradual transition from a dry climate to a wetter one during the Jurassic doesn't tell the whole story, says SMU paleontologist Timothy S. Myers, lead author on the study.

Geochemical analysis of ancient soils, called paleosols, revealed an unexpected and mysterious abrupt transition from dry to wet even though some of the samples came from two nearby locales, Myers said.

link.

Sauropod Niche Partitioning in the Late Jurassic Morrison Formation

How the largest animals to have ever walked the Earth fed, and how this allowed them to live alongside one another in prehistoric ecosystems is the subject of new research from the University of Bristol and the Natural History Museum, London.

The sauropods – large, long-necked plant-eating dinosaurs such as Diplodocus and Brachiosaurus – dominated the land between 210 and 65 million years ago. They were the largest land animals of all time, with the biggest weighing 80 tonnes (more than 11 elephants) and would have needed vast amounts of food.

Despite this, multiple sauropod species often lived alongside each other. The most notable example is the community of the Late Jurassic Morrison Formation, a distinctive sequence of sedimentary rock in the western United States from which over 10 species of sauropod are known.

How so many giant herbivores could have coexisted has long been a mystery: even the highly diverse faunas seen in modern Africa only support one truly gigantic species, the elephant. This is made even more puzzling by the harsh, semi-arid environment of the Morrison Formation during the Jurassic, which would have limited plant growth.

A study conducted by David Button, a PhD student in Bristol's School of Earth Sciences and the Natural History Museum, and colleagues used a novel combination of approaches to investigate this problem.

Although sauropods were gigantic, their heads were comparatively very small and so how they ingested enough food has puzzled many scientists. The researchers focussed on the skull and jaws of sauropods, using a variety of biomechanical techniques to investigate how they functioned and what this would mean for sauropod ecology.

Using CT scans, the researchers digitally reconstructed the skulls of the sauropods Camarasaurus and Diplodocus, along with the jaw and neck muscles of both species from the traces left on the bones where these muscles were attached in life. These two species are very common in the Morrison Formation, and are known to have widely co-existed. From this data, a biomechanical computer model of the skull of Camarasaurus was built using Finite Element Analysis (FEA), a modelling technique often employed in engineering and design to calculate stress and strain distribution in complex shapes. This model was then compared to a pre-existing model of Diplodocus in order to investigate how the dinosaurs fed.

David Button said: "Our results show that although neither could chew, the skulls of both dinosaurs were sophisticated cropping tools. Camarasaurus had a robust skull and strong bite, which would have allowed it to feed on tough leaves and branches. Meanwhile, the weaker bite and more delicate skull of Diplodocus would have restricted it to softer foods like ferns. However, Diplodocus could also have used its strong neck muscles to help it detach plant material through movements of the head. This indicates differences in diet between the two dinosaurs, which would have allowed them to coexist."

The researchers also used a series of biomechanical measurements from other sauropod species to calculate the functional disparity in their skulls and jaws and found that other Morrison Formation sauropods were also highly varied in feeding adaptations, suggesting different diets.

Co-author, Professor Emily Rayfield of the University of Bristol said: "In modern animal communities differences in diet such as this – termed 'dietary niche partitioning' – allow multiple similar species to coexist by reducing competition for food. Although, dietary niche partitioning has been suspected between Morrison Formation sauropods based on their structural features and patterns of tooth-wear, this is the first study to provide strong, numerical, biomechanical evidence for its presence in this fossil community."

link.

paper link.

Bristle Like Scales in Ornithischian Dinosaurs From Tithonian (?) Jurassic Russia

A new type of skin derivatives in Ornithischian dinosaurs from the late Jurassic of Transbaikalia (Russia)

Authors:

Saveliev et al

Abstract:

none.

Note: there is some sort of dispute over the fossils.

A Tithonian Jurassic Hydrocarbon Seep's Marine Fossil Snapshot

Hydrocarbon seeps from close to the Jurassic–Cretaceous boundary, Svalbard

Authors:

Hammer et al

Abstract:

Fifteen carbonate bodies, interpreted as having been formed at hydrocarbon seeps, have been found in the Sassenfjorden area of Spitsbergen, Svalbard. The bodies, up to 5 m wide, are found in the siltstones and mudstones of the uppermost Slottsmøya Member, in the Upper Jurassic to lowermost Cretaceous Agardhfjellet Formation. The age of the seeps is close to the Volgian–Ryazanian (Jurassic–Cretaceous) boundary, and the Mjølnir impact event in the Barents Sea. The Sassenfjorden area carbonates show complex and heterogeneous structures typical of hydrocarbon seeps, including zoned (botryoidal) cement textures, fissure-infilling sparite, and breccias. Stable isotope analyses show highly negative δ13C values (down to ca. −43‰ VPDB) in the zoned carbonate cements, consistent with authigenic precipitation in a hydrocarbon-rich environment. Oxygen isotopes indicate secondary hydrothermal activity. The species-rich, well-preserved fauna includes at least 13 species of small to medium sized bivalves, some of which are abundant, as well as rarer rhynchonelliform and lingulid brachiopods, gastropods, echinoderms, sponges, and serpulid and probable vestimentiferan worm tubes. Although several bivalves (solemyids, lucinids, and probably Thyasira and Nucinella) had chemosymbionts, the Sassenfjorden seep fauna contains few, if any, seep obligate taxa, consistent with formation in a relatively shallow-water paleoenvironment. The seeps contain the earliest record of thyasirid bivalves, and a species-rich (six) brachiopod fauna including the first lingulid recorded in a seep environment. Ammonites, belemnites and large wood fragments represent ex situ fossils in the seep carbonate bodies.

Surprise! Upper Jurassic Morrison Formation had Conifer Forests

Greater palaeobiodiversity in conifer seed cones in the Upper Jurassic Morrison Formation of Utah, USA

Authors:

Gee et al

Abstract:

Although fossil conifer wood, leaves, and pollen have been known from the Upper Jurassic Morrison Formation of the Western Interior of North America for many decades, only a few conifer seed cones have been described as carbonaceous compressions and casts with little internal structure. Recently, however, over 60 silicified seed cones with preserved internal anatomy were amassed by collectors from 11 localities in northeastern and southern Utah and brought to the attention of palaeobotanists. Here we describe the silicified cones from Utah and compare them to one another in size, gross morphology and internal construction. The fossil material is sorted into five new morphotypes of seed cone. Morphotype 1 pertains to Araucariaceae, Morphotype 2 is most likely Pinaceae, and Morphotype 5 is Cheirolepidiaceae. The familial affinity of Morphotypes 3 and 4 cannot be determined at this time. Comparative size analysis based on volume calculations shows that Morphotypes 2, 3, 4 and 5 are extremely small, smaller than any Mesozoic araucarian seed cone, and that Morphotype 1 falls within the range of small fossil araucarian cones. Most cone-bearing localities are situated to the northwest, west, and south of Hanksville in southcentral Utah. With regard to palaeobiodiversity, if Araucaria delevoryasii Gee from Wyoming is included, there are now six morphotypes of seed cones that represent at least three conifer families in Utah and Wyoming. Because many conifers are arborescent and form forests, the new fossil evidence suggests that species-diverse conifer forests or woodlands were a major type of vegetation in the Morrison Formation during the Late Jurassic.

Oldest Record of Azhdarchid Pterosaurs in Africa From Kimmeridgian/Tithonian Jurassic Tanzania

New pterosaur material from the Upper Jurassic of Tendaguru (Tanzania), Africa

Authors:

Costa et al

Abstract:

The pterosaur fossil record from Africa is exceedingly scarce and one of the least known for any continental land mass. The specimens here described are housed at the Naturkundemuseum of the Humboldt University and consist of two cervical vertebrae, a coracoid and a wing metacarpal recovered from the Upper Jurassic Tendaguru Formation, Tanzania. Due to the general morphology and the absence of a lateral pneumatic foramen in both vertebrae, as well as the presence of a longitudinal depression, not previously reported in pterosaurs, we consider these specimens as representatives of a new species of Azhdarchidae. Moreover, because the coracoid, which bears three well-developed pneumatic foramina, has a well-excavated depression that is medially positioned at the posterior face of the acrocoracoid process, we regard this as a new basal pterodactyloid species. The wing metacarpal is greatly elongated and clearly belongs to Pterodactyloidea. Its elongation and slender aspect, as well as the sub-triangular shape of its proximal articular end, likely place it within the Tapejaroidea. The material here described shows the potential of these deposits to provide more informative pterosaur material and provisionally extends the oldest record of azhdarchids to the Kimmeridgian–Tithonian of Africa.

Docodon apoxys: A New Docodon Species From Oxfordian/Kimmeridgian/Tithonian Jurassic Colorado

A New Species of Docodon (Mammaliaformes: Docodonta) from the Upper Jurassic Morrison Formation and a Reassessment of Selected Craniodental Characters in Basal Mammaliaforms

Authors:

Rougier et al

Abstract:

We describe a new species of the basal mammaliaform Docodon, D. apoxys, sp. nov., represented by three nearly complete dentaries from the Upper Jurassic Morrison Formation of central Colorado. This species differs from other known species of Docodon in the relative heights of the principal molar cusps and in the size of the distal molars. In addition, we attribute a partial rostrum preserving much of the maxilla and most of the premaxilla, bearing a complete incisor and premolar count, to Docodon sp. These materials supply previously unknown morphology for this classic North American Jurassic taxon, and help establish a common morphology for Docodonta as a whole. While Docodon differs from the Portuguese docodont Haldanodon in the presence of only five upper incisors (none of which is entirely within the maxilla), an internarial bar is present in both taxa. The new specimens also unambiguously preserve a complete and undistorted angular process that differs conspicuously from the classical interpretation of the holotype of Docodon victor; this structure in docodonts closely resembles the angular process in australosphenidans and trechnotheres. We abandon the concept of a “pseudangular” process and we consider the angular process to be a homologous feature (where present) across Mammaliaformes.

A Lagerstätte From Tithonian Jurassic France

Palaeontology of the Purbeck-type (Tithonian, Late Jurassic) bonebeds of Chassiron (Oléron Island, western France)

Authors:

Vullo et al

Abstract:

The paralic flora and fauna from the Late Jurassic of Chassiron (Oléron Island, western France) are described. The Tithonian-aged bonebeds of Purbeck facies of this locality have yielded a rich and diverse vertebrate assemblage including fishes, amphibians, reptiles and mammals, alongside numerous plant and invertebrate remains. The Chassiron locality thus appears as a peculiar Konzentrat-Lagerstätte in which most of the palaeoecosystem's biological components (both aquatic and terrestrial) have been preserved. The depositional environment was probably subject to salinity fluctuations, as indicated by the co-occurrence of freshwater and euryhaline organisms. This is one of the richest localities and the first mammal-bearing site known from the Jurassic of France.

Torvosaurus gurneyi the Largest Land Predator of Kimmeridgian-Tithonian Jurassic Europe

Torvosaurus gurneyi n. sp., the Largest Terrestrial Predator from Europe, and a Proposed Terminology of the Maxilla Anatomy in Nonavian Theropods

Authors:

Hendrickx et al

Abstract:

The Lourinhã Formation (Kimmeridgian-Tithonian) of Central West Portugal is well known for its diversified dinosaur fauna similar to that of the Morrison Formation of North America; both areas share dinosaur taxa including the top predator Torvosaurus, reported in Portugal. The material assigned to the Portuguese T. tanneri, consisting of a right maxilla and an incomplete caudal centrum, was briefly described in the literature and a thorough description of these bones is here given for the first time. A comparison with material referred to Torvosaurus tanneri allows us to highlight some important differences justifying the creation of a distinct Eastern species. Torvosaurus gurneyi n. sp. displays two autapomorphies among Megalosauroidea, a maxilla possessing fewer than eleven teeth and an interdental wall nearly coincidental with the lateral wall of the maxillary body. In addition, it differs from T. tanneri by a reduced number of maxillary teeth, the absence of interdental plates terminating ventrally by broad V-shaped points and falling short relative to the lateral maxillary wall, and the absence of a protuberant ridge on the anterior part of the medial shelf, posterior to the anteromedial process. T. gurneyi is the largest theropod from the Lourinhã Formation of Portugal and the largest land predator discovered in Europe hitherto. This taxon supports the mechanism of vicariance that occurred in the Iberian Meseta during the Late Jurassic when the proto-Atlantic was already well formed. A fragment of maxilla from the Lourinhã Formation referred to Torvosaurus sp. is ascribed to this new species, and several other bones, including a femur, a tibia and embryonic material all from the Kimmeridgian-Tithonian of Portugal, are tentatively assigned to T. gurneyi. A standard terminology and notation of the theropod maxilla is also proposed and a record of the Torvosaurus material from Portugal is given.

Kimmeridgian/Tithonian Jurassic Sauropod Lourinhasaurus is Really a Camarasaur

Phylogenetic reassessment of Lourinhasaurus alenquerensis, a basal Macronaria (Sauropoda) from the Upper Jurassic of Portugal

Authors:

Mocho et al

Abstract:

Lourinhasaurus alenquerensis is a Portuguese Upper Jurassic dinosaur whose lectotype is one of the most complete sauropod specimens from the Portuguese fossil record and from the Upper Jurassic of Europe. It was recovered from sediments of the Sobral Formation (upper Kimmeridgian to lower Tithonian) at Moinho do Carmo (Alenquer, Portugal). The lectotype of Lourinhasaurus was first related to Apatosaurus and then tentatively related to Camarasaurus. Finally, it was established as a new taxon, Lourinhasaurus, including the Moinho do Carmo specimen. At the time of writing, Lourinhasaurus had a poor diagnosis and an unstable phylogenetic position. Revision of the Moinho do Carmo specimen has led to a detailed description and a new and more complete codification for several morphological characters. The phylogenetic analyses proposed herein considered Lourinhasaurus as a Camarasauromorpha Macronaria. This study also recovered a Camarasauridae clade incorporating Lourinhasaurus, Camarasaurus and, putatively, Tehuelchesaurus and that implies the presence of Camarasauridae in the European Upper Jurassic. Besides the strong similarity to Camarasaurus, Lourinhasaurus alenquerensis is here considered a valid taxon with 13 putative autapomorphies such as a sagittal keel on the dorsal margin of sacral neural spines, circular and deep spinoprezygapophyseal fossa on proximal caudal vertebrae, marked crest and groove bordering the lateral margin of the acetabulum in the ischium, and a marked deflection of the entire femoral shaft without lateral bulge. The apparently high number of taxa among the sauropod fauna from the Iberian Peninsula during the Late Jurassic is similar to the palaeobiodiversity recorded in formations of the same age, i.e. Morrison and Tendaguru, and does not support the hypothesis of a connection between the North America and Iberian Peninsula faunas during the later part of the Late Jurassic reflected by other faunal and floral groups.

Kimmeridgian/Tithonian Jurassic Spain's Ecology Always had at Least two Megatheropods

Megatheropods as apex predators in the typically Jurassic ecosystems of the Villar del Arzobispo Formation (Iberian Range, Spain)

Authors:

Cobos et al

Abstract:

The limestone, sandstone and clays of the Villar del Arzobispo Formation (Kimmeridgian–Berriasian) crop out in the south of the Iberian Range (Spain), and from a palaeontological point of view, the formation is characterised by dozens of sites with dinosaur fossils. The most abundant are the sauropods and stegosaurs, while the ornithopods are scarce, and theropods (especially large–sized ones) are very rare. Here are described some fossils of large–sized theropods (a new tooth and a tridactyl trackway) found at two sites of this formation within the Peñagolosa sub–basin (Maestrazgo Basin) in Teruel province. The new tooth from Formiche Alto is attributed to a large indeterminate tetanuran, possibly a megalosaurid, and is closely related to other large fossil teeth from this formation in Riodeva and Galve (Teruel) and Alpuente (Valencia). In addition, a distinctive morphology of the large–sized tridactyl footprints in the trackway found at the El Castellar tracksite at the village of the same name, allows the establishment of a new ichnotaxon, Iberosauripus grandis ichnogen. et ichnosp. nov. It is easily differentiated from a number of previously named ichnotaxa and suggests the ichnological record of large theropods from the Upper Jurassic of Europe, North America and Asia can be divided into two distinct groups, whose trackmakers were probably members of Megalosauridae and Allosauridae. Keeping in mind that smaller and also different teeth related to allosaurids have been previously described, it is concluded that the dinosaur assemblages in this formation include at least two types of large–sized megatheropod tetanurans which, when fully grown, were responsible for the large–sized tridactyl footprints found in this unit. The predation pressure exerted by these theropods can be seen as a significant cause stimulating the gigantic sizes of some sauropods (like Turiasaurus and Losillasaurus) found in the same formation.

Yet Another New Pterosaur: A Pterodacytloid From Tithonian Jurassic Argentina

New fossil record of a jurassic pterosaur from neuquen basin, vaca muerta formation, argentina

Authors:

Laura Codorniú and Alberto Garrido

Abstract:

Discoveries of Jurassic pterosaurs in the Southern Hemisphere are extremely unusual. In Argentina, pterosaurs from the Upper Jurassic (Tithonian) have only been found in the Northwest of Patagonia (Neuquén Basin). These come from marine deposits and three specimens have been discovered up to the present. In this paper, we report a new finding from the Neuquén Basin. This material is identified as a tibiotarsus, which probably belonged to an osteologically adult individual and represents a new species of a pterodactyloid pterosaur of medium size. This discovery provides new evidence that at least two different species of pterodactyloid pterosaurs may have coexisted in the shallow marine deposits of the Neuquén Basin.