A FEATHERED Dinosaur Tail Found Trapped in Amber From Cenomanian Cretaceous Myanmar

A Feathered Dinosaur Tail with Primitive Plumage Trapped in Mid-Cretaceous Amber

Authors:

Xi et al

Abstract:

In the two decades since the discovery of feathered dinosaurs, the range of plumage known from non-avialan theropods has expanded significantly, confirming several features predicted by developmentally informed models of feather evolution. However, three-dimensional feather morphology and evolutionary patterns remain difficult to interpret, due to compression in sedimentary rocks. Recent discoveries in Cretaceous amber from Canada, France, Japan, Lebanon, Myanmar, and the United States reveal much finer levels of structural detail, but taxonomic placement is uncertain because plumage is rarely associated with identifiable skeletal material. Here we describe the feathered tail of a non-avialan theropod preserved in mid-Cretaceous (∼99 Ma) amber from Kachin State, Myanmar, with plumage structure that directly informs the evolutionary developmental pathway of feathers. This specimen provides an opportunity to document pristine feathers in direct association with a putative juvenile coelurosaur, preserving fine morphological details, including the spatial arrangement of follicles and feathers on the body, and micrometer-scale features of the plumage. Many feathers exhibit a short, slender rachis with alternating barbs and a uniform series of contiguous barbules, supporting the developmental hypothesis that barbs already possessed barbules when they fused to form the rachis. Beneath the feathers, carbonized soft tissues offer a glimpse of preservational potential and history for the inclusion; abundant Fe2+ suggests that vestiges of primary hemoglobin and ferritin remain trapped within the tail. The new finding highlights the unique preservation potential of amber for understanding the morphology and evolution of coelurosaurian integumentary structures.

Gualicho shinyae: a Neovenatorid Carcharodontosaurian Theropod With a Tyrannosaur-like Hand From Cenomanian Cretaceous Argentina

An Unusual New Theropod with a Didactyl Manus from the Upper Cretaceous of Patagonia, Argentina

Authors:

Apesteguía et al

Abstract:

Background

Late Cretaceous terrestrial strata of the Neuquén Basin, northern Patagonia, Argentina have yielded a rich fauna of dinosaurs and other vertebrates. The diversity of saurischian dinosaurs is particularly high, especially in the late Cenomanian-early Turonian Huincul Formation, which has yielded specimens of rebacchisaurid and titanosaurian sauropods, and abelisaurid and carcharodontosaurid theropods. Continued sampling is adding to the known vertebrate diversity of this unit.

Methodology/ Principal Findings

A new, partially articulated mid-sized theropod was found in rocks from the Huincul Formation. It exhibits a unique combination of traits that distinguish it from other known theropods justifying erection of a new taxon, Gualicho shinyae gen. et sp. nov. Gualicho possesses a didactyl manus with the third digit reduced to a metacarpal splint reminiscent of tyrannosaurids, but both phylogenetic and multivariate analyses indicate that didactyly is convergent in these groups. Derived characters of the scapula, femur, and fibula supports the new theropod as the sister taxon of the nearly coeval African theropod Deltadromeus and as a neovenatorid carcharodontosaurian. A number of these features are independently present in ceratosaurs, and Gualicho exhibits an unusual mosaic of ceratosaurian and tetanuran synapomorphies distributed throughout the skeleton.

Conclusions/ Significance

Gualicho shinyae gen. et sp. nov. increases the known theropod diversity of the Huincul Formation and also represents the first likely neovenatorid from this unit. It is the most basal tetatanuran to exhibit common patterns of digit III reduction that evolved independently in a number of other tetanuran lineages. A close relationship with Deltadromaeus from the Kem Kem beds of Niger adds to the already considerable biogeographic similarity between the Huincul Formation and coeval rock units in North Africa.

pop sci write up.

Electroblemma bifid: A Bizarre ARMORED Spider in Amber From Cenomanian Cretaceous Myanmar

A bizarre armoured spider (Araneae: Tetrablemmidae) from Upper Cretaceous Myanmar amber

Authors:

Selden et al

Abstract:

A new genus and species of tetrablemmid spider, Electroblemma bifida n. gen. et sp., is described, from two adult males found in Upper Cretaceous (Cenomanian) amber of Myanmar. The genus is distinguished by its enormous dorsal carapace projection and highly modified chelicerae. The new genus is referred to the tribe Tetrablemmini within the subfamily Tetrablemminae. The presence of a relatively derived tetrablemmid on the south-east Eurasian continent during the Late Cretaceous suggests that the family was already well diversified in tropical rainforests at this time.

Camouflage Evolution in Albian/Cenomanian Cretacous Insect Preserved in Amber

Those who go to a masked ball consciously slip into a different role, in order to avoid being recognized so quickly. Insects were already doing something very similar in the Cretaceous: They cloaked themselves in pieces of plants, grains of sand, or the remains of their prey, in order, for example, to be invisible to predators. An international research team, with participation from the University of Bonn, has now investigated such "invisibility cloaks" encased in amber. The custom-tailored "costumes" also permit conclusions about the habitat at the time. The results have now been published in the journal "Science Advances".

The larva of the lacewing attacks a pseudoscorpion and uses its powerful mouthparts to suck it dry. The larva then puts the remains of the dead prey on its back. The outlines of the lacewing are now unrecognizable. It looks more like a dead pseudoscorpion. This camouflage protects the lacewing against being recognized by predators and at the same makes it easier to hunt its own prey. "With this 'disguise', the lacewing larva pretends to be someone completely different", says Prof. Dr. Jes Rust of the Steinmann-Institute of the University of Bonn. "Using the pieces of its prey, it even takes on the smell of the pseudoscorpion".

The scene plays out in the Cretaceous and is recorded as a "snapshot" in amber. A research team under Dr. Bo Wang of the State Key Laboratory of Paleobiology and Stratigraphy in Nanjing (China) worked together with paleontologists from the University of Bonn and other scientists from China, USA, France, and England to examine a total of 35 insects preserved in amber. With the aid of grains of sand, plant residue, wood fibers, dust, or even the lifeless shells of their victims, the larvae achieved camouflage to perfection. The amber samples come from Myanmar, France, and Lebanon.

link.

An enigmatic aquatic snake from the Cenomanian Cretaceous Venezuela

An enigmatic aquatic snake from the Cenomanian of Northern South America

Authors:

Albino et al

Abstract:

We report the first record of a snake from the Cretaceous of northern South America. The remains come from the La Luna Formation (La Aguada Member, Cenomanian of Venezuela) and consist of several vertebrae, which belong to the precloacal region of the vertebral column. Comparisons to extant and extinct snakes show that the remains represent a new taxon, Lunaophis aquaticus gen. et sp nov. An aquatic mode of life is supported by the ventral position of the ribs, indicating a laterally compressed body. The systematic relationships of this new taxon are difficult to determine due to the scarcity of fossil material; it is, however, a representative of an early lineage of snakes that exploited tropical marine pelagic environments, as reflected by the depositional conditions of the La Aguada Member. Lunaophis is also the first aquatic snake from the Cenomanian found outside of the African and European Tethyan and Boreal Zones.

Lizards Preserved in Albian/Cenomanian Cretaceous Amber From Myanmar

Mid-Cretaceous amber fossils illuminate the past diversity of tropical lizards

Authors:

Daza et al

Abstract:

Modern tropical forests harbor an enormous diversity of squamates, but fossilization in such environments is uncommon and little is known about tropical lizard assemblages of the Mesozoic. We report the oldest lizard assemblage preserved in amber, providing insight into the poorly preserved but potentially diverse mid-Cretaceous paleotropics. Twelve specimens from the Albian-Cenomanian boundary of Myanmar (99 Ma) preserve fine details of soft tissue and osteology, and high-resolution x-ray computed tomography permits detailed comparisons to extant and extinct lizards. The extraordinary preservation allows several specimens to be confidently assigned to groups including stem Gekkota and stem Chamaleonidae. Other taxa are assignable to crown clades on the basis of similar traits. The detailed preservation of osteological and soft tissue characters in these specimens may facilitate their precise phylogenetic placement, making them useful calibration points for molecular divergence time estimates and potential keys for resolving conflicts in higher-order squamate relationships.

Ichthyosaurs Went Extinct During Cenomanian Cretaceous due to Inability to Adapt to Radical Climate Change

Ichthyosaurs - shark-like marine reptiles from the time of dinosaurs - were driven to extinction by intense climate change and their own failure to evolve quickly enough, according to new research by an international team of scientists.

The study provides an explanation for one of the longest-standing enigmas in palaeobiology: how and why ichthyosaurs died out. Unlike other marine reptile groups, ichthyosaurs disappeared tens of millions of years before the end-Cretaceous extinction (65 million years ago) that marked the end for dinosaurs and the beginning of the age of mammals.

The research is published in the journal Nature Communications.

First author Dr Valentin Fischer, of the University of Liège, Belgium, and the University of Oxford, UK, said: "We analysed the extinction of this crucial marine group thoroughly for the first time. We compared the diversity of ichthyosaurs with the geological record of global change, emphasising the dynamics of these datasets.

"Ichthyosaurs were actually well diversified during the last chapter of their reign, with several species, body shapes and ecological niches present. However, their evolution was much slower than earlier in their history. Additionally, they were seemingly negatively affected by the profound global changes going on during the Cretaceous, as their extinction rate correlates with environmental volatility."

Causes of extinctions - including the demise of the ichthyosaurs, or 'sea dragons' - have often remained elusive and conjectural, particularly when they cannot be linked to an obvious geological or geochemical event such as a large meteorite or massive volcanic eruption. Ichthyosaurs were regarded as undiversified for a prolonged period before their extinction, and their dying out has previously been linked to minor events including increased competition with other marine predators and a decline in their assumed principal source of food.

However, using a battery of cutting-edge techniques to quantify ancient biodiversity and its fluctuations, the team was able to reconstruct the evolution of the ichthyosaurs during the last 120 million years of their lifetime and assess the causes of their extinction. The researchers - comprising Belgian, British, French and Russian scientists - demonstrated that before their extinction, ichthyosaurs were in fact highly diverse, both in terms of body shape and ecological role.

A two-phase event then suppressed their ecological diversity and wiped out the group at the beginning of the Late Cretaceous period, about 100 million years ago. At that time, the Earth's poles were essentially ice-free, and sea levels were much higher than today. Analyses revealed that this two-phase extinction can be associated both with reduced evolutionary rates (a failure to evolve novel body plans for a prolonged period) and intense climate change (strong variations in sea surface temperatures and sea levels).

link.

paper link.

How big did Your Abelisaur Grow? (and explaining Stromer's Riddle)

A large abelisaurid (Dinosauria, Theropoda) from Morocco and comments on the Cenomanian theropods from North Africa

Authors:

Chiarenza et al

Abstract:

We describe the partially preserved femur of a large-bodied theropod dinosaur from the Cenomanian “Kem Kem Compound Assemblage” (KKCA) of Morocco. The fossil is housed in the Museo Geologico e Paleontologico “Gaetano Giorgio Gemmellaro” in Palermo (Italy). The specimen is compared with the theropod fossil record from the KKCA and coeval assemblages from North Africa. The combination of a distally reclined head, a not prominent trochanteric shelf, distally placed lesser trochanter of stout, alariform shape, a stocky shaft with the fourth trochanter placed proximally, and rugose muscular insertion areas in the specimen distinguishes it from Carcharodontosaurus, Deltadromeus and Spinosaurus and supports referral to an abelisaurid. The estimated body size for the individual from which this femur was derived is comparable to Carnotaurus and Ekrixinatosaurus (up to 9 meters in length and 2 tons in body mass). This find confirms that abelisaurids had reached their largest body size in the “middle Cretaceous,” and that large abelisaurids coexisted with other giant theropods in Africa. We review the taxonomic status of the theropods from the Cenomanian of North Africa, and provisionally restrict the Linnean binomina Carcharodontosaurus iguidensis and Spinosaurus aegyptiacus to the type specimens. Based on comparisons among the theropod records from the Aptian-Cenomanian of South America and Africa, a partial explanation for the so-called “Stromer’s riddle” (namely, the coexistence of many large predatory dinosaurs in the “middle Cretaceous” record from North Africa) is offered in term of taphonomic artifacts among lineage records that were ecologically and environmentally non-overlapping. Although morphofunctional and stratigraphic evidence supports an ecological segregation between spinosaurids and the other lineages, the co-occurrence of abelisaurids and carcharodontosaurids, two groups showing several craniodental convergences that suggest direct resource competition, remains to be explained.

pop sci link too.

A Possible Ceratopsian Found in Cenomanian Cretaceous Utah

A possible juvenile ceratopsoid ilium from the Cenomanian of central Utah, U.S.A.

Authors:

Carpenter et al

Abstract:

We describe a small ilium, with fibrous texture characteristic of juvenile bone, from the lower Cenomanian of central Utah, U.S.A. The ilium was recovered from the upper part of the Mussentuchit Member of the Cedar Mountain Formation. The ilium most closely resembles that of immature ceratopsid ilia referred to Agujaceratops mariscalensis from the Campanian Aguja Formation of southern Texas, U.S.A. Both have everted dorsal margins over the iliac body, subhorizontal postacetabular processes, and laterally compressed, anteroventrally curved preacetabular processes. If correctly identified, the small ilium from the Cedar Mountain Formation is the oldest ceratopsid or ceratopsoid known, and shows that the diversity of early ceratopsians was greater than previously realized.

Evidence of an Early Cenomanian Cretaceous “Hot Greenhouse” Paleoclimate

Early Cenomanian “hot greenhouse” revealed by oxygen isotope record of exceptionally well-preserved foraminifera from Tanzania

Authors:

Ando et al

Abstract:

The search into Earth's mid-Cretaceous greenhouse conditions has recently been stimulated by the Tanzania Drilling Project (TDP) which has recovered exceptionally well-preserved biogenic carbonates from subsurface pre-Neogene marine sediments in the eastern margin of central Africa. Published Tanzanian oxygen isotope records measured on exquisitely preserved foraminiferal tests, dating to as old as ~93 Ma, provided evidence for a Turonian “hot greenhouse” with very high and stable water-column temperatures. We have generated a comparable dataset of exceptionally well-preserved foraminifera from a lower Cenomanian interval of TDP Site 24 spanning 99.9–95.9 Ma (planktonic foraminiferal Thalmanninella globotruncanoides Zone; nannofossil Corollithion kennedyi to Lithraphidites eccentricus Zones), thereby extending the age coverage of the Tanzanian foraminiferal δ18O record back by ~7 million years. Throughout the interval analyzed, the new foraminiferal δ18O data are consistently around −4.3‰ for surface-dwelling planktonic taxa and −1.9‰ for benthic Lenticulina spp., which translate to conservative paleotemperature estimates of greater than 31 °C at the surface and greater than 17 °C at the sea floor (upper bathyal depths). Considering the ~40°S Cenomanian paleolatitude of TDP Site 24, these estimates are higher than computer simulation results for accepted “normal” greenhouse conditions (those with up to 4× preindustrial pCO2 level) and suggest that the climate mode of the early Cenomanian was very similar to the Turonian hot greenhouse. Taking account of other comparable data sources from different regions, the hot greenhouse mode within the normal mid-Cretaceous greenhouse may have begun by the latest Albian, but the precise timing of the critical transition remains uncertain.

Cimoliopterus dunni: a new Toothed Pterosaur From Cenomanian Cretaceous Texas

First North American occurrence of the toothed pteranodontoid pterosaur Cimoliopterus

Author:

Myers

Abstract:

A new pterosaur species, Cimoliopterus dunni, sp. nov., is described based on a partial rostrum from the upper Cenomanian Britton Formation in the Eagle Ford Group of north-central Texas. The holotype preserves alveoli for a minimum of 26 upper teeth and bears a thin premaxillary crest that begins above the fourth pair of alveoli. The rostrum, characterized by a slight lateral flare, lacks the pronounced lateral expansion found in ornithocheirids and anhanguerids. The tip of the snout is small and blunt, and the anterior face of the rostrum is oriented posteroventrally, forming an approximately 45° angle with the anterior portion of the palate. The anteroventrally oriented first pair of alveoli is directed more ventrally than anteriorly. Phylogenetic analysis suggests that Cimoliopterus dunni and Cimoliopterus cuvieri, from the Cenomanian Grey Chalk Subgroup in Kent, England, are basal pteranodontoids that are closely related to Aetodactylus halli from the middle Cenomanian Tarrant Formation of north Texas. Cimoliopterus dunni marks only the second known occurrence of Cimoliopterus, extending its geographic range from Europe to North America. In conjunction with Coloborhynchus wadleighi from the upper Albian Pawpaw Formation, Cimoliopterus dunni provides unambiguous evidence of biogeographic linkages between the pterosaur faunas of North America and Europe in the middle Cretaceous.

Climatic Implications of Ginkgoites waarrensis in the Cenomanian Cretaceous Antarctic

Climatic implications of Ginkgoites waarrensis Douglas emend. from the south polar Tupuangi flora, Late Cretaceous (Cenomanian), Chatham Islands

Authors:

Mays et al

Abstract:

The flora of the Cenomanian–Turonian (ca. 96–90 Ma) Tupuangi Formation, Chatham Islands, New Zealand, was inhabiting a region well within the south polar circle (~ 70–80° S) during the early Late Cretaceous, an interval characterised by extreme global greenhouse conditions. The Tupuangi flora offers a unique perspective into an ecological and environmental setting which has no extant analogue, whilst providing proxies of polar palaeoclimatic conditions during a phase of extreme global warming. Ginkgoites waarrensis Douglas, 1965 (emended herein), a species known previously from a single occurrence in Australia, is an abundant element of the Tupuangi flora. Forty-five leaf samples from three localities are reported, and a systematic treatment of this species revealed a wide morphological range. In contrast to the exclusively riparian niche of more recent members of Ginkgoales, associated sedimentological and palaeoecological data suggest that this species had an ecological preference for regularly disturbed, coastal deltaic settings. Herein, we review the geographic and stratigraphic distributions of Cretaceous Gondwanan ginkgoalean leaf taxa. An increasing diversity of this group from the Early Cretaceous to the early Late Cretaceous supports a broader trend of floral provincialisation throughout this interval, most likely driven by concurrent global transgression and active tectonic extension across southern Gondwana. Carbon dioxide has been inferred as a primary proximate cause of the mid-Cretaceous global greenhouse. The leaf cuticles of Ginkgoites waarrensis were utilised to approximate atmospheric carbon dioxide (pCO2) during the Cenomanian. Stomatal index (SI) data were collected from ten specimens, and the stomatal ratio method yielded a semi-quantitative pCO2 estimate of 1150–1350 ppmv, which is consistent with modelled and proxy estimates of the Cenomanian. The present study explores the inherent limitations of the transfer function method for estimating CO2 when applied to taxa with very low SI values, such as G. waarrensis. In addition to pCO2, temperature and irradiance are identified as environmental variables which may have systematically promoted the low SI of G. waarrensis, but their combined influence is likely mitigated by the relatively high temperature of this region during the mid-Cretaceous and the high summer insolation at polar latitudes.

The Albian/Maastrichtian Cretaceous Vertebrate Fauna of India's Cauvery Basin

Cretaceous vertebrate fauna of the Cauvery Basin, southern India: Palaeodiversity and palaeobiogeographic implications

Author:

Verma

Abstract:

The vertebrate fauna from the late Albian to Maastrichtian succession of the Cauvery Basin, south India has been known since 1845, but it received only scant attention as compared to the vertebrates already known from the Deccan volcanic province of peninsular India. Recent fossil discoveries appear to support the emergence of significantly diverse marine and non-marine vertebrates comprising fishes, frogs, reptiles (ichthyosaurs, plesiosaurs, turtles, crocodiles and dinosaurs) and a mammal from the Cauvery Basin have revived the interest in the fauna of the basin as it has significant implications for understanding the palaeobiogeography of India. The latest Albian to Turonian marine vertebrates such as sharks, ichthyosaurs and plesiosaurs show a wide geographic distribution and marine territory, while sharks are typically cooler water fauna of high palaeolatitudes. The latest Maastrichtian non-marine vertebrates especially turtles, crocodiles, dinosaurs and a mammal are considered to show mixed Gondwanan and Laurasian affinities thus providing new lines of evidence in favour of a latest Cretaceous biotic links between India and the neighbouring continents. An overview of the vertebrate faunal diversity of the Cretaceous sequences of the Cauvery Basin and its palaeobiogeographic considerations are presented.

Bone Eating Worms Originally Evolved to eat Marine Reptiles, not Whales

A species of bone-eating worm that was believed to have evolved in conjunction with whales has been dated back to prehistoric times when it fed on the carcasses of giant marine reptiles.

Scientists at Plymouth University found that Osedax - popularised as the 'zombie worm' - originated at least 100 million years ago, and subsisted on the bones of prehistoric reptiles such as plesiosaurs and sea turtles.

Reporting in the Royal Society journal Biology Letters this month, the research team at Plymouth reveal how they found tell-tale traces of Osedax on plesiosaur fossils held in the Sedgwick Museum at the University of Cambridge.

Dr Nicholas Higgs, a Research Fellow in the Marine Institute, said the discovery was important for both understanding the genesis of the species and its implications for fossil records. "The exploration of the deep sea in the past decades has led to the discovery of hundreds of new species with unique adaptations to survive in extreme environments, giving rise to important questions on their origin and evolution through geological time." said Nicholas. "The unusual adaptations and striking beauty of Osedax worms encapsulate the alien nature of deep-sea life in public imagination.

"And our discovery shows that these bone-eating worms did not co-evolve with whales, but that they also devoured the skeletons of large marine reptiles that dominated oceans in the age of the dinosaurs. Osedax, therefore, prevented many skeletons from becoming fossilised, which might hamper our knowledge of these extinct leviathans."

link.

Cenomanian Cretaceous Morocco Have a Spinosaur Dominated Paleoecology

Overabundance of piscivorous dinosaurs (Theropoda: Spinosauridae) in the mid-Cretaceous of North Africa: The Algerian dilemma

Authors:

Benyoucef et al

Abstract:

The informally called ‘Continental intercalaire’ is a series of continental and brackish deposits that outcrops in several regions of North Africa. The age of the series is not well-constrained, but its upper part, visible in the ‘Kem Kem beds’ in Morocco and in Bahariya in Egypt, is regarded as early Cenomanian in age. Spinosaurid remains are an important component of this series, but records of this dinosaur are surprisingly rare in Algerian localities of the ‘Continental intercalaire’. Here, we describe a vertebrate assemblage from two localities, Kénadsa and Menaguir, situated in the Guir basin, Western Algeria. The assemblage comprises hybodont sharks, sarcopterygian fishes, ray-finned fishes, turtles, crocodiles and dinosaurs. Among the latter, only teeth of theropods have been recovered and 94% belong to Spinosaurus. The assemblage is taxonomically very similar to the Moroccan and Egyptian assemblages mentioned above. This study: 1) suggests a likely early Cenomanian age for the Guir basin deposits containing the assemblage; 2) provides a new evidence of the homogeneity of the early Cenomanian vertebrate fauna throughout North Africa; and 3) confirms the overabundance of theropod dinosaurs, especially spinosaurs, in the assemblage showing a possible shortcut in the vertebrate food chain. The northern most locality, Menaguir, shows sedimentological and ichnological evidence of marine influences indicating that the palaeoenvironment shows spatial heterogeneities.

Evidence of Albian/Cenomanian Cretaceous Environmental Pertubation From Peru

Record of Albian to early Cenomanian environmental perturbation in the eastern sub-equatorial Pacific

Authors:

Navarro-Ramirez et al

Abstract:

The present paper documents and discusses a new Albian–early Cenomanian carbon isotope (δ13Ccarb and δ13Corg) curve from the subequatorial Eastern Pacific in Peru. Chemostratigraphic evidences for the expression of the OAE1b set and for OAE1c and OAE1d are presented. This dataset is relevant inasmuch as previous work is strongly biased towards study sites in North America (Western Interior Basin), in Europe (Tethys) and the Pacific realm. A comparison of the carbon isotope stratigraphy obtained in Peru with published sections from the Central and Western Pacific, the Western Atlantic and Northern and Western Tethys reveals an overall good agreement supporting the global nature of the isotope patterns described here. The δ13C from Peru record is constrained by biostratigraphic evidence and 87Sr/86Sr isotope stratigraphy using well-preserved oyster shells. Furthermore, we document the development of a heterozoan epeiric-neritic mixed carbonate-siliciclastic ramp in the Western Platform of Peru and its corresponding sedimentary facies associations. This dataset was used to elucidate the complex interplay of climatic changes, nutrient supply, and platform drowning, leading to the following conclusions: (i) An upper Aptian–lower Albian major change from siliciclastic-dominated to carbonate sedimentation coincided with the impact of the Kilian Level. (ii) A lower Albian incipient platform drowning linked to the impact of the Paquier Level. (iii) A lower middle Albian major demise of neritic carbonate production that coincides with the Leenhardt Level, followed by middle Albian condensed sedimentation that reports prominent negative values in δ13Ccarb prior to the onset of OAE1c. (4) Finally, renewed carbonate ramp production during the upper Albian–lower Cenomanian. The data shown here represent the foundation for future work documenting the mid–Cretaceous of Peru and its implications for the palaeoceanography of the SE subequatorial Pacific.

Great Trippin Titanosaurs! Grass, Ergot Fungus Found in Amber From Albian/Cenomanian Cretaceous Myanmar

A perfectly preserved amber fossil from Myanmar has been found that provides evidence of the earliest grass specimen ever discovered - about 100 million years old - and even then it was topped by a fungus similar to ergot, which for eons has been intertwined with animals and humans.

Ergot has played roles as a medicine, a toxin, and a hallucinogen; been implicated in everything from disease epidemics to the Salem witch trials; and more recently provided the hallucinogenic drug LSD.

Apparently both ergot and the grasses that now form most of the diet for the human race evolved together.

And if they already seemed a little scary, imagine a huge sauropod dinosaur that just ate a large portion of this psychotropic fungus, which in other animal species can cause anything from hallucinations to delirium, gangrene, convulsions or the staggers. The fungus, the grasses it lived on and dinosaurs that ate grass co-existed for millions of years.

The findings and analysis of this remarkable fossil were just published online in the journal Palaeodiversity, by researchers from Oregon State University, the USDA Agricultural Research Service and Germany.

"It seems like ergot has been involved with animals and humans almost forever, and now we know that this fungus literally dates back to the earliest evolution of grasses," said George Poinar, Jr., an internationally recognized expert on the life forms found in amber and a faculty member in the OSU College of Science.

"This is an important discovery that helps us understand the timeline of grass development, which now forms the basis of the human food supply in such crops as corn, rice or wheat," Poinar said. "But it also shows that this parasitic fungus may have been around almost as long as the grasses themselves, as both a toxin and natural hallucinogen.

"There's no doubt in my mind that it would have been eaten by sauropod dinosaurs, although we can't know what exact effect it had on them."

link.

PaleoClimate Change Across the Albian/Cenomannian Cretaceous Transition

Paleoclimatic reconstruction for the Albian–Cenomanian transition based on a dominantly angiosperm flora from the Cedar Mountain Formation, Utah, USA

Authors:

Arens et al

Abstract:

The Soap Wash flora from the Cedar Mountain Formation of Emery County, Utah (Albian–Cenomanian boundary) consists almost entirely of angiosperms and is positioned stratigraphically near the first appearance of flowering plants in this region. We applied both univariate (leaf margin analysis—LMA, and leaf area analysis—LAA) and multivariate (Climate Leaf Analysis Multivariate Program—CLAMP) methods to the 17 morphotypes recognized in the flora to reconstruct palaeoclimate. LMA produced a mean annual temperature (MAT) estimate ranging from 19 °C to 26 °C. CLAMP yielded 16 °C–18 °C. LAA produced a mean annual precipitation (MAP) of 81 cm, while CLAMP generated a mean growing season precipitation of 134–187 cm, within the range of standard error for the LAA estimation. CLAMP also estimated a nine to ten month growing season with some temperature seasonality and substantial seasonality in precipitation. This reconstruction is broadly consistent with sedimentological data that suggested a semiarid to monsoonal precipitation regime for the region and with climate models that predict warm summers and strong winter seasonality in precipitation. Leaf physiognomic parameters of the Soap Wash flora fall within the range of variation circumscribed by the calibration sets of all three methods, so the differences in reconstructed MAT values cannot be explained exclusively by this kind of systematic error. We propose two alternative hypotheses: First, modern leaf form-climate relationships may not yet have evolved. This seems unlikely because CLAMP has been successfully applied to older material elsewhere. Second, the Soap Wash flora may be out of equilibrium with its prevailing climate due to contemporaneous rapid climate flux. If correct, this pattern may suggest a link between mid-Cretaceous environmental perturbations and the rapid diversification and geographic spread of flowering plants.

Petrified Wood Growth Indices as Climate Proxies For Cenomanian/Turonian Cretaceous Australia

Wood growth indices as climate indicators from the Upper Cretaceous (Cenomanian–Turonian) portion of the Winton Formation, Australia

Authors:

Fletcher et al

Abstract:

Although the mid- to Late Cretaceous is regarded as a global warm period, increasingly a more complex picture of warming and cooling is emerging. New techniques allow more precise dating of terrestrial localities, opening opportunities for using climate proxy approaches on terrestrial fauna and flora to better capture the complexity of Cretaceous climate. Here an attempt is made to understand the seasonality and inter-annual variability of two newly dated localities from the upper preserved portion (Cenomanian–Turonian) of the Winton Formation, Australia. Primarily quantitative approaches to palaeodendrology are used. The results suggest both seasonality and high variability in climate conditions that affect growth between years, including evidence for floods. The longest series (QM F44338) suggests oscillatory patterns of good and poor growth in a 15 year alternating cycle similar to the contemporary Pacific Decadal Oscillation, although other potential explanations should be considered and tested.

Wood Growth Rings From Cenomanian/Turonian Cretaceous Australia as Paleoclimate Indicators

Wood growth indices as climate indicators from the Upper Cretaceous (Cenomanian–Turonian) portion of the Winton Formation, Australia

Authors:

Fletcher et al

Abstract:

Although the mid- to Late Cretaceous is regarded as a global warm period, increasingly a more complex picture of warming and cooling is emerging. New techniques allow more precise dating of terrestrial localities, opening opportunities for using climate proxy approaches on terrestrial fauna and flora to better capture the complexity of Cretaceous climate. Here an attempt is made to understand the seasonality and inter-annual variability of two newly dated localities from the upper preserved portion (Cenomanian–Turonian) of the Winton Formation, Australia. Primarily quantitative approaches to palaeodendrology are used. The results suggest both seasonality and high variability in climate conditions that affect growth between years, including evidence for floods. The longest series (QM F44338) suggests oscillatory patterns of good and poor growth in a 15 year alternating cycle similar to the contemporary Pacific Decadal Oscillation, although other potential explanations should be considered and tested.