Wiehenvenator albati (aka the Monster von Minden): a new Megalosaurid Theropod From Callovian Jurassic Germany

A new megalosaurid theropod dinosaur from the late Middle Jurassic (Callovian) of north-western Germany: implications for theropod evolution and faunal turnover in the Jurassic

Authors:

Rauhut et al

Abstract:

Fragmentary remains of a large, robustly built theropod dinosaur were recovered from the marine middle Callovian Ornatenton Formation of north-eastern Northrhine-Westphalia, Germany. The specimen includes a premaxilla, maxilla, lacrimal, postorbital, dentary, several caudal vertebrae, ribs, fibulae, astragalus, and partial calcaneum. It is here described as a new species of megalosauroid, Wiehenvenator albati n. gen. n. sp., diagnosed by a strongly reduced maxillary antorbital fossa on the base of the ascending process of the maxilla, a very short anterior ramus of the lacrimal with an additional pneumatic depression anteroventral to the lacrimal fenestra, a transversely expanded orbital facet in the postorbital, and a laterally flexed proximal end of the ascending process of the astragalus. Phylogenetic analysis recovers Wiehenvenator as a megalosaurine megalosaurid, sister taxon to the Late Jurassic genus Torvosaurus. It thus adds to the considerable diversity of megalosauroids in the Middle Jurassic. A time-calibrated phylogeny of theropods indicates a rapid radiation of averostran theropods between the Toarcian and the Bathonian. This radiation was probably triggered by the Pliensbachian-Toarcian extinction event, which might have been more important for theropod evolution than the Triassic-Jurassic extinction. The fossil record indicates a faunal turnover from megalosauroid dominated Middle Jurassic to allosauroid / coelurosaur dominated Late Jurassic faunas. However, differences in the Middle and Late Jurassic theropod fossil records both in respect to geographic distribution of localities, as well as sampled environments make this inference problematic, at least in respect to allosauroids. An analysis of environmental preferences of allosauroids and megalosauroids indicates that the former preferred inland environments, whereas the latter are more common in nearshore environments.

Better Retcon Your Angiosperm (Flowering Plant) Origin Story! Herbaceous Angiosperm Found From Callovian Jurassic China

A Whole Plant Herbaceous Angiosperm from the Middle Jurassic of China

Authors:

Han et al

Abstract:

In contrast to woody habit with secondary growth, truthful herbaceous habit lacking secondary growth is restricted to angiosperms among seed plants. Although angiosperms might have occurred as early as in the Triassic and herbaceous habit theoretically may have been well adopted by pioneer angiosperms, pre-Cretaceous herbs are missing hitherto, leaving the origin of herbs and evolution of herbaceous angiosperms mysterious. Here we report Juraherba bodae gen. et sp. nov, a whole plant herbaceous angiosperm, from the Middle Jurassic (greater than 164 Ma) at Daohugou Village, Inner Mongolia, China, a fossil Lagerst?tten that is worldwide famous for various fossil finds. The angiospermous affinity of Juraherba is ensured by its enclosed ovules/seeds. The plant is small but complete, with physically connected hairy root, stem, leaves, and fructifications. The Middle Jurassic age recommends Juraherba as the earliest record of herbaceous seed plants, demanding a refresh look at the evolutionary history of angiosperms.

There was no "‘Northern Branch of Neotethys” During the Jurassic

Where are the remnants of a Jurassic ocean in the eastern Mediterranean region?

Authors:

Eyuboglu et al

Abstract:

The subduction polarity of Tethyan oceanic lithosphere during Jurassic is a controversial topic in relation to the geodynamic evolution of the Alpine–Himalayan system. We present new geological, geochemical and zircon U–Pb data from four different regions of the Eastern Pontides Orogenic Belt, a key area of the Alpine–Himalayan system. We discuss the origin of the magmatism and also the existence of an ocean in the eastern Mediterranean region during the Jurassic period. Jurassic intrusions, predominantly gabbro, tonalite and minor diorite, are well exposed in the southern and axial zones of the orogenic belt. Thermobarometry indicates that high-pressure (6–10 kb) crystallization of these intrusions occurred at temperatures of 1183–1250 °C. Zircon U–Pb dating from 10 samples show ages between 195 and 165 Ma, indicating that magmatism occurred between Sinemurian and Callovian time. We characterize the intrusions from electron microprobe, zircon geochronology, and whole rock and Sr, Nd, and Pb isotopes. Our data show that the studied intrusions are broadly tholeiitic, except for two calc-alkaline bodies, and formed in an arc-related setting with minimal involvement of older crust or sediment.

The most widely accepted model proposes that the ultramafic–mafic rocks exposed between the Pontide arc and the Tauride belt are remnants of a Jurassic Penrose-type and/or suprasubduction zone ophiolite. However, new zircon U–Pb age data from mafic lithologies cutting the Kop ultramafic massif do not support this model and clearly indicate that the ultramafic lithologies are Paleozoic or older in age and are not remnants of a Jurassic ocean that known as ‘’Northern Branch of Neotehtys”.

Evidence of Well Mixed PeriTethys Basins in the Late Callovian/Early Kimmeridgian Jurassic Jura Mountains in Poland?

Seawater temperatures and carbon isotope variations in central European basins at the Middle–Late Jurassic transition (Late Callovian–Early Kimmeridgian)

Author:

Wierzbowski

Abstract:

Oxygen and carbon isotope values and elemental ratios of well-preserved belemnite rostra, brachiopod shells and bulk-carbonates from the Upper Callovian–Lower Kimmeridgian of the Polish Jura Chain, Kujawy (Poland) and Swabian Alb (Germany) are investigated to reconstruct environmental conditions and perturbations in the marine carbon cycle. Belemnite δ18O values show relatively constant temperatures (ca. 12 °C) of bottom waters in the Polish Jura Chain basin during a major part of the Late Callovian–Middle Oxfordian, except for a short-term cooling (to ca. 9 °C) at the Callovian–Oxfordian transition. Belemnite and brachiopod δ18O values show a gradual increase in temperature during the Submediterranean Late Oxfordian; the highest temperatures (ca. 16 °C) are calculated for the Submediterranean Oxfordian–Kimmeridgian transition. Belemnite and brachiopod Mg/Ca and Sr/Ca ratios are disregarded as a paleotemperature proxy because of their weak correlation with δ18O values.

The belemnite and brachiopod isotope data confirm that the carbon isotope composition of belemnite rostra is affected by a metabolic effect, which results in a depletion of belemnite calcite in the 13C isotope. Belemnite rostra are considered, nevertheless, as a valuable tracer of temporal variations in the carbon isotope composition of marine carbonates. Belemnite δ13C data show the presence of two positive excursions (in the Upper Callovian and the Middle Oxfordian) in the carbon isotope record of peri-Tethyan carbonates. The excursions are divided by a Lower Oxfordian interval characterized by decreased δ13C values. This is most likely a regional feature caused by upwelling. Lowest belemnite and brachiopod δ13C values are observed in the lower part of the Submediterranean Upper Oxfordian and are linked to a well-mixed state of the seawater in the basins studied. The carbon isotope record of bulk carbonates differs from those of belemnites and brachiopods probably because of strong variations in carbonate production in the Polish Jura Chain basin.

Yi qi: The Bizzaro World Feathered *AND* Bat Winged Freak, ahem, Scansoriopterygid Maniraptor Theropod From Callovian/Oxfordian Jurassic China

A bizarre Jurassic maniraptoran theropod with preserved evidence of membranous wings

Authors:

Xu et al

Abstract:

The wings of birds and their closest theropod relatives share a uniform fundamental architecture, with pinnate flight feathers as the key component. Here we report a new scansoriopterygid theropod, Yi qi gen. et sp. nov., based on a new specimen from the Middle–Upper Jurassic period Tiaojishan Formation of Hebei Province, China. Yi is nested phylogenetically among winged theropods but has large stiff filamentous feathers of an unusual type on both the forelimb and hindlimb. However, the filamentous feathers of Yi resemble pinnate feathers in bearing morphologically diverse melanosomes. Most surprisingly, Yi has a long rod-like bone extending from each wrist, and patches of membranous tissue preserved between the rod-like bones and the manual digits. Analogous features are unknown in any dinosaur but occur in various flying and gliding tetrapods, suggesting the intriguing possibility that Yi had membranous aerodynamic surfaces totally different from the archetypal feathered wings of birds and their closest relatives. Documentation of the unique forelimbs of Yi greatly increases the morphological disparity known to exist among dinosaurs, and highlights the extraordinary breadth and richness of the evolutionary experimentation that took place close to the origin of birds.

Palaeobiogeography of the Bajocian/Oxfordian Jurassic Sinai

Palaeobiogeography of the Bajocian–Oxfordian macrofauna of Gebel Maghara (North Sinai, Egypt): Implications for eustacy and basin topography

Authors:

Abdelhady et al

Abstract:

Based on newly collected material from the Bajocian–Oxfordian rocks of Gebel Maghara (North Sinai, Egypt) and available published information, the palaeobiogeographic pattern and the dispersal potential of the macrofauna including bivalves, ammonites, corals, and brachiopods are investigated. Both clustering methods and ordination techniques were applied and evaluated. During Bajocian times, G. Maghara occupied an intracratonic setting and was isolated from the main ocean by islands and shallows. These barriers may have limited the dispersal potential of the macrofauna and impeded the faunal exchange with even nearby areas. Although these barriers had disappeared by rejuvenation of faults during an active rift stage in Bathonian times, the same biogeographic patterns continued, which may be related to the global sea level lowstand. By Callovian times, a time of global sea level highstand, in contrast, the fauna of the study area became very similar to that of northeastern Africa. Similarly, diversity and extinction rates increased from the middle Bathonian onward, which may reflect intrusion of cosmopolitan taxa due to the newly established open marine setting and the global sea level highstand. Towards the Oxfordian, lowering of temperature may have limited the dispersal ranges of the macrofauna within the Ethiopian Province. As a result, a southeastern subprovince (Indo–Malagasy) including Tanzania, Madagascar, and India became established. Although the geographic patterns of the different faunal groups exhibit some similarities resulting from abiotic factors such as sea level, climate, and basin topography, biotic characteristics such as life habits and larval development played the dominant role in shaping the distribution pattern. The dispersal potential was highest for ammonites, followed by that of corals and then bivalves. Brachiopods had the lowest dispersal potential.

Jurassic Park Needs Parasites! Callovian Jurassic Fly Larva Volunteers!

Around 165 million years ago, a spectacular parasite was at home in the freshwater lakes of present-day Inner Mongolia (China): A fly larva with a thorax formed entirely like a sucking plate. With it, the animal could adhere to salamanders and suck their blood with its mouthparts formed like a sting. To date no insect is known that is equipped with a similar specialised design. The international scientific team is now presenting its findings in the journal "eLIFE".

The parasite, an elongate fly larva around two centimeters long, had undergone extreme changes over the course of evolution: The head is tiny in comparison to the body, tube-shaped with piercer-like mouthparts at the front. The mid-body (thorax) has been completely transformed underneath into a gigantic sucking plate; the hind-body (abdomen) has caterpillar-like legs. The international research team believes that this unusual animal is a parasite which lived in a landscape with volcanoes and lakes what is now northeastern China around 165 million years ago. In this fresh water habitat, the parasite crawled onto passing salamanders, attached itself with its sucking plate, and penetrated the thin skin of the amphibians in order to suck blood from them.

"The parasite lived the life of Reilly", says Prof. Jes Rust from the Steinmann Institute for Geology, Mineralogy and Palaeontology of the University of Bonn. This is because there were many salamanders in the lakes, as fossil finds at the same location near Ningcheng in Inner Mongolia (China) have shown. "There scientists had also found around 300,000 diverse and exceptionally preserved fossil insects", reports the Chinese scientist Dr. Bo Wang, who is researching in palaeontology at the University of Bonn as a PostDoc with sponsorship provided by the Alexander von Humboldt Foundation. The spectacular fly larva, which has received the scientific name of "Qiyia jurassica", however, was a quite unexpected find. "Qiyia" in Chinese means "bizarre"; "jurassica" refers to the Jurassic period to which the fossils belong.

link.

Daohugou Biota From a Lagerstatte of Jurassic China is Distinct From the Jehol Biota

The vertebrates of the Jurassic Daohugou Biota of northeastern China

Authors:

Sullivan et al

Abstract:

The Early Cretaceous Jehol Biota of northeastern China has become famous over the last two decades as a source of feathered avialan and non-avialan theropods, preserved alongside an array of other fossil vertebrates, invertebrates, and plants. Still more recently, a rich assemblage referred to in this paper as the Daohugou Biota has begun to emerge from Jurassic strata in the same region. Like their counterparts from the Jehol Biota, Daohugou Biota vertebrate specimens are typically preserved in fine-grained lacustrine beds and often retain feathers and other soft-tissue features. At present, 30 vertebrate taxa (five salamanders, one anuran, two lizards, 13 pterosaurs, five dinosaurs, and four mammals) are known from the Daohugou Biota, which was first recognized at the Daohugou locality in Inner Mongolia. The presence of the salamander Chunerpeton tianyiensis, proposed in this paper as an index fossil for the Daohugou Biota, links the Daohugou locality to five other fossil-producing areas in the provinces of Hebei and Liaoning. The strata containing the Daohugou Biota are close to the Middle–Upper Jurassic boundary and belong at least partly to the regionally widespread Tiaojishan Formation. In general, the vertebrate fauna of the Daohugou Biota is strikingly different from that of the Jehol Biota, although paravian dinosaurs, anurognathid pterosaurs, and salamanders with cryptobranchid and hynobiid affinities occur in both. Nevertheless, the Daohugou Biota and the Jehol Biota are two successive Lagerstätte assemblages that collectively offer a taphonomically consistent window into the Mesozoic life of northeast Asia over a significant span of geologic time.

Excellent Mating Insects Fossils From Callovian Jurassic China

Forever Love: The Hitherto Earliest Record of Copulating Insects from the Middle Jurassic of China

Authors:

Shu Li, Chungkun Shih, Chen Wang, Hong Pang and Dong Ren

Abstract:

Background

Mating behaviors have been widely studied for extant insects. However, cases of mating individuals are particularly rare in the fossil record of insects, and most of them involved preservation in amber while only in rare cases found in compression fossils. This considerably limits our knowledge of mating position and genitalia orientation during the Mesozoic, and hinders our understanding of the evolution of mating behaviors in this major component of modern ecosystems.

Principal Finding

Here we report a pair of copulating froghoppers, Anthoscytina perpetua sp. nov., referable to the Procercopidae, from the Middle Jurassic of northeastern China. They exhibit belly-to-belly mating position as preserved, with male's aedeagus inserting into the female's bursa copulatrix. Abdominal segments 8 to 9 of male are disarticulated suggesting these segments were twisted and flexed during mating. Due to potential taphonomic effect, we cannot rule out that they might have taken side-by-side position, as in extant froghoppers. Genitalia of male and female, based on paratypes, show symmetric structures.

Conclusions/Significance

Our findings, consistent with those of extant froghoppers, indicate froghoppers' genitalic symmetry and mating position have remained static for over 165 million years.

Eileanchelys waldmani: Transitional Turtle

(image credit: BBC)

Fossils of the earliest known swimming turtles have been uncovered on an island in northwest Britain, scientists reported today.

The fossils of the previously unknown species suggest turtles first took to water during the Middle Jurassic period (180 to 160 million years ago).

Four crushed but intact skeletons had been found along with the remains of two other specimens, in a single slab of rock in 2004 on Scotland's Isle of Skye. Since then, researchers have painstakingly freed the fossils.

The fossils belonged to a pond turtle, Eileanchelys waldmani, which bridges the evolutionary gap between primitive land turtles and modern aquatic turtles.

Turtles first appeared in the Triassic period some 210 million years ago. They were exclusively land creatures, said study team member Jérémy Anquetin, a French Ph.D. student at the Natural History Museum in London.

These earliest turtles were heavy, lumbering creatures armed with thick shells and protective spikes, he said.

But the new fossil turtle had a domed, tortoise-like shell measuring up to 11.8 inches (30 centimeters) long and it was much more delicately built.

"It's light framed, just like an aquatic turtle," Anquetin said.

"Until the discovery of Eileanchelys, we thought that adaptation to aquatic habitat might have appeared among primitive turtles, but we had no fossil evidence of that," he added.

"Now we know for sure that there were aquatic turtles around 164 million years ago," Anquetin said.

Kewl! Callovian anapsida fossils! Woot! BBC also has a very nice science article on the subject. Whew. I was worried I'd only get HPC related posts out today.