A Lamniform Shark From Albian Cretaceous Texas Grew 6.3m (20+ ft) in 18 Years

Ontogeny and life history of a large lamniform shark from the Early Cretaceous of North America

Authors:

Frederickson et al

Abstract:

Due to an incomplete fossil record, little is known about lamniform shark life history from the Early Cretaceous of North America. Recent discoveries have shown that during this time, some lamniformes reached gigantic sizes (greater than 6–8 m in total length) not seen in earlier species. Given the importance of life history to understand how organisms reach such sizes, we conducted an ontogenetic analysis on three very large shark vertebrae, representing a single individual from the Lower Cretaceous (Albian) Duck Creek Formation of Texas. Using three different techniques (computed tomography, histological sectioning, and surface texture analysis), we were able to show that this individual was born at a relatively small size and subsequently grew at rapid rate, achieving a total length of over 6.3 m in approximately 18 years; a rate not observed in any other Cretaceous species. Comparison of the different aging techniques yielded complementary results; however, surface texture analysis produced the most complete ontogenetic record for this specimen. More work is needed to determine broad patterns in the life history evolution of giant Early Cretaceous lamniform sharks.

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.

Giant Sharks From the Devonian/Carboniferous Boundary in Texas

Previously, giant sharks had only been recovered from rock dating back 130 million years, during the age of the dinosaurs. The largest shark that ever lived, commonly called "Megalodon", is much younger, with an oldest occurrence at about 15 million years ago. This means the new fossils from Texas indicate giant sharks go much further back into the fossil record.

After the generous donation of these fossils and careful study with Dr. John Maisey of the American Museum of Natural History in New York, the team was able to estimate how big the entire sharks would have been by comparison with smaller and more complete fossils of closely related sharks. The results were very impressive.

The size range estimated for these two Texas 'supersharks' was between 18 and 26 feet in length (5.5 to 8 meters). The largest of these specimens was 25% bigger than today's largest predatory shark, the Great White. Although not nearly as large as Megalodon, which might have reached up to 67 feet in length (about 20 meters), the fossil sharks from Texas would have been by far the biggest sharks in the sea.

link.

The Postcranial Skeleton of Elamosaurid Libonectes morgani From Turonian Cretaceous Texas

Postcranium of the paradigm elasmosaurid plesiosaurian Libonectes morgani (Welles, 1949)

Authors:

Sachs et al

Abstract:

Elasmosauridae constitutes one of the most immediately recognizable plesiosaurian radiations. Their distinctive body plan represents the popular model for Plesiosauria, and is typified by an osteological morphology especially adapted for hyper-elongation of the neck. Nevertheless, many archetypal elasmosaurids are known only from incomplete and/or inadequately documented material, a problem that has contributed to their uncertain intra-clade relationships. A prime example of this is Libonectes morgani from the Upper Cretaceous of Texas, USA, which is frequently presented as an elasmosaurid structural proxy because of its three-dimensionally preserved holotype skull. Perplexingly though, both the taxonomic diagnosis and phylogenetic placement of L. morgani rely primarily upon the cervical vertebrae, together with the pectoral girdle and forelimb, yet most of these elements are now lost and figured only as line drawings. We therefore reviewed the remnant postcranial skeleton of L. morgani first-hand with the objective of clarifying its defining character states. Our observations showed that the existing diagnosis of L. morgani is indeed inadequate. Moreover, the only identifiable autapomorphies occurred within the axial skeleton. This concurred with an examination of character scores used in published plesiosaurian phylogenies, and highlights the persistent significance of postcranial elements for discriminating elasmosaurid taxa.

Did Small Theropods Compete With Varanid Lizards in the Tropics of Campanian Cretaceous Texas?

A theropod tooth assemblage from the lower Aguja Formation (early Campanian) of West Texas, and the roles of small theropod and varanoid lizard mesopredators in a tropical predator guild

Authors:

Wick et al

Abstract:

A theropod tooth assemblage from the lower shale member of the Aguja Formation in West Texas is part of a diverse microvertebrate fauna, designated the Lowerverse local fauna, of early Campanian age (c. 80 – 82 Ma). The fauna includes as many as nine distinct theropod taxa along with several indeterminate archosaurs and birds. Theropod tooth types (indeterminate tyrannosaurids, cf. Saurornitholestes, cf. Richardoestesia, cf. Paronychodon) are similar to those found in the upper shale member of the Aguja, as well as in other Campanian theropod assemblages from western North America. However, the most abundant tooth morphotype is unique, and attributed to a new varanoid lizard with remarkably theropod-like dentition, herein designated Dryadissector shilleri (gen. et sp. nov.). The presence of many unique theropod tooth morphotypes in the Lowerverse local fauna suggests that there remains significant undiscovered diversity among small theropods in southern latitude faunas, and accords with recognition of distinct latitudinal biomes during Campanian time in western North America. Due to their similar dentition, small theropods, along with varanoid lizards, may have served similar ecological roles as competitive mesopredators in the Campanian tropical predator guild.

Chagas in the PreColumbian Pecos Canyonlands

Prehistoric Earth Oven Facilities and the Pathoecology of Chagas Disease in the Lower Pecos Canyonlands

Authors:

Reinhard et al

Abstract:

Understanding the endemic region of a disease is part of developing a concept of the disease’s natural history and its threat to human health in both ancient and modern times. Chagas disease is caused by the parasite Trypanosoma cruzi and has recently been identified as an emergent disease in North America. Ancient endemicity and reemergence has been demonstrated by an examination of a mummy found on the border between Coahuila, Mexico and Texas, USA. This mummified man, who died over 1,000 years ago, exhibits the gross pathology of megacolon, which is consistent with Chagas disease. We are now exploring the human behavior that resulted in this parasitic infection. Trypanosoma cruzi infection exists in a sylvatic cycle involving woodrats (Neotoma spp.) and triatomine insects (Triatoma spp.) in the lower Lower Pecos Canyonlands. The Archaic subsistence strategy may have impacted this life cycle directly through predation on wood rats and through the construction of baking pits. This would have expanded the habitat suitable for both woodrats and triatomine insects. We are proposing that archaeologists develop field methods to test this hypothesis.

A Titanosaur Sauropod From Maastrichtian Cretaceous Texas

New specimens of a titanosaur sauropod from the Maastrichtian of Big Bend National Park, Texas

Authors:

Fronimos et al

Abstract:

New specimens of a titanosaur sauropod from Maastrichtian strata in Big Bend National Park, Texas, include well-preserved dorsal vertebrae in association with pelvic elements. Anterior dorsal vertebrae are characterized by postspinal and centroprezygapophyseal laminae, with spinodiapophyseal laminae convergent on the anterior base of the neural spine. Posterior dorsal vertebrae are characterized by postzygodiapophyseal laminae and divided spinodiapophyseal laminae, with spinoprezygapophyseal laminae contributing to the prespinal lamina. The ilium and pubis differ from specimens previously collected, indicating a greater morphological disparity among titanosaurs in the Maastrichtian of West Texas than previously recognized. This disparity may be attributable to intraspecific variation or to the presence of multiple taxa. The new material is compatible with the only presently known North American titanosaur, Alamosaurus sanjuanensis, but is not formally referred due to lack of overlap with the hypodigm of that species. Comparison with other derived titanosaurs finds the closest affinities to Trigonosaurus pricei, Uberabatitan riberoi, and Baurutitan britoi of the Upper Cretaceous Brazilian Bauru Group, consistent with a South American immigration event at the end of the North American sauropod hiatus.

Cenomanian-Turonian Cretaceous Paleooceanic Environmental Conditions in South Texas

The Cenomanian-Turonian Eagle Ford Group of South Texas: Insights on timing and paleoceanographic conditions from geochemistry and micropaleontologic analyses

Authors:

Denne et al

Abstract:

The interbedded organic-rich marls and limestones of the Eagle Ford Group of South Texas were deposited on the shelf of the Central Texas Platform during the upper Cenomanian through the Turonian. Micropaleontological analyses of thin-sections and residue samples from subsurface cores taken in Atascosa and Karnes counties yielded 13 biostratigraphic datums, which were integrated with calcareous nannofossil datums, stable carbon isotopic and bulk inorganic geochemical analysis analysis to gain an understanding of the paleoceanographic conditions of the study area and their relationship to regional and global events. The paired thin-section / residue sampling was necessitated by poor recovery of planktonic foraminifera in washed samples, which were, however, abundant in most thin-sections. Lower Eagle Ford marls were deposited under euxinic conditions produced by a stratified water column. Periodic enhanced water column mixing increased oxygen levels and surface-water primary productivity, which promoted calcite diagenesis and generation of limestones containing calcispheres and radiolaria. An oxygenated bottom water mass entered the basin in the uppermost Cenomanian prior to the onset of Oceanic Anoxic Event (OAE) 2, causing a spike in benthic foraminiferal diversity and decreasing preservation of organic matter. Although the lower portion of the upper Eagle Ford is age-equivalent to OAE2 as indicated by positive shift in δ13Corg, it contains less organic matter and evidence of more oxygen than the lower Eagle Ford, so deposition of the Eagle Ford black shales is not contemporaneous to OAE2.

Sweetman Might be on to Something: USAF Neither Confirms nor Denies Texas Mystery Plane

The identity of what appears to be a blended wing-body aircraft type photographed over Amarillo, Texas, on March 10 remains uncertain, with the U.S. Air Force declining any comment on the aircraft.

Three aircraft were observed flying in formation southwest of Amarillo around 4:20 p.m. CDT, by photographers on the fence line of the city's international airport. IbOne of the aircraft could be a B-2, but the clearest color photos and monochrome images enhanced (for contrast and resolution) with commercial software suggest a blended shape with a straight trailing edge. Steve Douglass, one of the photographers and an experienced aircraft observer, says the aircraft were “larger than fighter-size” and appeared similar in wingspan to commercial traffic.

The formation was not using Mode S transponders, according to a review of records at the Flightradar24 air-traffic-tracking site. Radio transmissions apparently associated with the flight were intercepted and recorded, possibly including the call sign “Sienna.”

An Air Force representative in Washington responded to queries about the aircraft, and about flight activities at that time and place, with the statement “I have nothing for you,” a phrase long associated with responses to queries about classified programs and operations. The 509th Bomb Wing at Whiteman AFB, Mo., home of the Air Force's B-2 fleet, says that none of its aircraft were operating near Amarillo on March 10. However, test units have also flown B-2s.

The fact that three aircraft were in formation suggests an aircraft that is operational or close to reaching that status. The unidentified aircraft are not likely to have been examples of the Northrop Grumman stealth reconnaissance drone known as the RQ-180 (AW&ST Dec. 9, 2013, p. 20) because unmanned air systems are seldom flown in formation of any kind. Likewise, the Lockheed Martin demonstrator that is reportedly being built to support the Long Range Strike-Bomber program is likely to be a one-off product.

link.

Sweetman @ AvLeak Claims Plane Chasers in Texas Find Mystery Aircraft

As far as I know, this sort of thing has happened only once since 1956.

That was when British magazines started getting eyewitness accounts and grainy photos of the Lockheed U-2, then operating out of RAF Lakenheath on its first spy flights over the Soviet Union. Classified programs have been exposed in all sorts of ways since then - for example, the A-12 Blackbird was disclosed under a degree of pressure - but until the RQ-170 Sentinel was seen at Kandahar in 2007-09 there has been no such aircraft photographed before it was declassified. (And in the case of the RQ-170, the operational security people were not trying too hard.)

With that in mind, let's look at the photos taken by Steve Douglass and Dean Muskett of an aircraft seen over Amarillo on March 10.

link.

hmmm.  I remember the doughnuts on a rope pix from the late 80s early 90s as well.

Alamosaurus sanjuanensis From Maastrichtian Cretaceous West Texas

A complete titanosaur femur from West Texas with comments regarding hindlimb posture

Authors:

Wick et al

Abstract:

An isolated titanosaur femur recovered from the Javelina Formation (Maastrichtian) of Big Bend National Park, Texas is the most complete example yet reported from North America. The specimen is likely referable to Alamosaurus sanjuanensis, the only titanosaur thus far known from Upper Cretaceous strata in North America, but cannot be attributed with certainty to that taxon. Compared to femora from other titanosaurs, the specimen has a relatively reduced abductor crest, a less elevated femoral head, and a distal joint surface that is orthogonal to the long axis of the shaft. These differences suggest that the Big Bend femur pertains to a species where hindlimb stance was closer to vertical, and with a comparatively narrower gait than other titanosaurids.

Parabolic Arc Digs Into Blue Origins Plans

The FAA recently approved Blue Origin’s application to expand operations at its West Texas test site “to include new development vehicles, which would use liquid oxygen and liquid hydrogen propellants.”

The supplemental environmental assessment was required because of a shift in propellants used in flight tests. The FAA conducted an earlier review in 2006 when it originally approved the testing of reusable propulsion modules and crew capsules (CCs) at the site.

The Final Supplemental Environmental Assessment for the Blue Origin
West Texas Launch Site is a fascinating in that it provides an insight into the vehicles and test operations of the notoriously secretive company.

What follows are excerpts from the report outlining key elements of the company’s future test plans.

link.

Ankylosuchus chinlegroupensis: a new Badly Named Doswelliid Archosauromorph From Upper Triassic Texas

A new doswelliid archosauromorph from the Upper Triassic of West Texas.

Authors:

Lucas et al

Abstract:

Ankylosuchus chinlegroupensis is a new genus and species of heavily-armored archosauromorph from the Otischalkian Colorado City Formation of the Chinle Group in Howard County, West Texas. The incomplete holotype skeleton consists of cranial and pelvic (?) elements, vertebral centra, a partial limb shaft and numerous osteoderms. The skull elements reveal a thick, heavily armored braincase and skull roof with parasagittal crests. The relatively short sacral vertebrae suggest an animal less than 1 meter in total body length, not including the tail. The morphology of the osteoderms does not match any currently known armored archosauromorph, but it is most similar to doswelliids. Most of the osteoderms possess large, closely packed pits that form no obvious pattern. Some osteoderms have raised, linear ridges running across them and others have anterior laminae with faint patterning on the articular surface. Some of the osteoderms are tightly sutured to each other via digitate sutures; all are relatively thick. The patterning of the ostoderms matches well with that of doswellids in being coarse, deeply incised and mostly composed of equal-sized pits and in the possession of anterior laminae. Even so, these osteoderms are readily distinguished from those of Doswellia, the only doswelliid previously reported from the Chinle Group, by their coarser pitting, greater thickness and (at least in some osteoderms) fusion with laterally adjacent osteoderms along their mutual sutural boundaries. A. chinlegroupensis is derived from the oldest strata of the Texas Chinle Group, the Otischalkian, whereas the genus Doswellia is known from the Chinle Group in Texas, New Mexico and Utah, in strata of Otischalkian-Adamanian (late
Carnian) age. Doswelliids are very rare, but visible components of global Triassic faunas. They include Tarjadia (= Archeopelta) from the Berdyankian (Ladinian) of Argentina and Brazil, Doswellia from the Otischalkian-Adamanian of the American Southwest and the Otischalkian of the Newark Supergroup in the eastern USA, and now Ankylosuchus from the Otischalkian of West Texas.

How Many Dimetrodon Species Are Present in the Artinskian Permian Briar Creek Bonebed

Long bone histology indicates sympatric species of Dimetrodon (Lower Permian, Sphenacodontidae)

Authors:

Christen D. Shelton, P. Martin Sander, Koen Stein and Herman Winkelhorst

Abstract:

The Briar Creek Bonebed (Artinskian, Nocona Formation) in Archer County is one of the richest sources of Dimetrodon bones in the Lower Permian of Texas, USA. Based on size, a small (D. natalis), an intermediate (D. booneorum), and a large species (D. limbatus) have been described from this locality. It has been proposed that these traditionally recognised species represent an ontogenetic series of only one species. However, the ontogenetic series hypothesis is inconsistent with the late ontogenetic state of the small bones, as suggested by their osteology and degree of ossification. Histological analysis of newly excavated material from the Briar Creek Bonebed has resolved some of the discretion between these two competing hypothesis, confirming the coexistence of a small (D. natalis) with at least one larger Dimetrodon species. An external fundamental system is present in the largest sampled long bones identified as D. natalis. The histology of D. natalis postcrania is described as incipient fibro lamellar bone. This tissue is a combination of parallel-fibred and woven-fibred bone that is highly vascularised by incipient primary osteons. The species status of D. booneorum and D. limbatus remain unresolved.

Tyrannosauroid Theropods From Campanian Cretaceous Big Bend, Texas

Tyrannosauroid dinosaurs from the Aguja Formation (Upper Cretaceous) of Big Bend National Park, Texas

Authors:

Thomas M. Lehman and Steven L. Wick

Abstract:

Rare remains of tyrannosauroid dinosaurs from the Aguja Formation in West Texas indicate the presence here of a relatively gracile species, comparable in form and adult size to Appalachiosaurus or subadult albertosaurines, Gorgosaurus and Albertosaurus. Histologic analysis of one of the specimens indicates that the Aguja tyrannosaur attained an adult size substantially smaller than adult albertosaurines (700 kg, 6·5 m body length). The frontal bone is narrow with a wide orbital slot and a bipartite joint for the postorbital, features thought to be diagnostic of Albertosaurinae; but there is a tall sagittal crest and reduced parietal wedge separating the frontals on the midline, features thought to be diagnostic of Tyrannosaurinae. The tall sagittal crest may be a synapomorphy of Tyrannosaurinae, and the Aguja tyrannosaur is herein referred to that clade. However, the unique combination of character states exhibited by the frontal prevents confident attribution to any known species. The Aguja tyrannosaur provides further evidence that North American Campanian tyrannosauroids were remarkably diverse for such large predators, and that each species was apparently endemic to a relatively small geographic province.

New Hard Headed Texan (a dinosaur, guys, dinosaur)

Paleontologists have discovered a new species of dinosaur with a softball-sized lump of solid bone on top of its skull, according to a paper published in the April issue of the journal Cretaceous Research.

The species was a plant-eating dinosaur about as big as a medium-sized dog that lived 70 to 80 million years ago, said Nicholas Longrich of Yale University, lead author of the paper. The team discovered two skull fragments in Big Bend National Park in southwest Texas in 2008. They compared them to dozens of fossils from related species found in Canada and Montana before confirming that the fossils represented a new genus of pachycephalosaur, a group of bipedal, thick-skulled dinosaurs.

The researchers named the new species Texacephale langstoni. ("Texacephale" means "Texas head" and "langstoni" is in honor of Wann Langston, a fellow paleontologist.) The new species is one of about a dozen known to have solid lumps of bone on top of their skulls, which Longrich speculates was probably used to ram one another head-on in a manner similar to modern-day musk oxen and cape buffalo.

The discovery of the new species lends further weight to the idea, which has gained popularity in recent years, that dinosaurs found in Canada and the northern United States were distinct from their southern neighbors.

"Instead of roaming across the North American continent, we see pockets of different dinosaurs that are pretty isolated from one another," Longrich said. "Every time we get good fossils from Texas, they end up looking very different from those to the north."

Because fossils from the Big Bend region are rare and tend to be poorly preserved, scientists do not have a complete picture of the different species that once inhabited the area, Longrich said.

But the team may have uncovered an important piece of the puzzle with their discovery. They found that this particular group of dinosaurs, which was previously thought to have originated in Asia, likely evolved in North America.

Longrich expects more related species to be discovered in the future as fossils from the Texas site and elsewhere continue to be examined.

"I think we underestimate how many different species there were," he says.

That last quote is an interesting one. We underestimate the number of species runs in vast contrast to some other statements from other groups as of late.

Permian Basal Synapsid Cladistics

Eothyris and Oedaleops: Do These Early Permian Synapsids from Texas and New Mexico form a Clade?

1. Robert R. Reisz (A,*)
2. Stephen J. Godfrey (A,B)
3. Diane Scott (A)

A. Department of Biology, University of Toronto at Mississauga, 3359 Mississauga Road, Mississauga, Ontario, L5L 1C6, Canada, robert.reisz@utoronto.ca;

B. Present Address: Department of Paleontology, Calvert Marine Museum, P.O. Box 97, Solomons, Maryland, 20688, U.S.A., Godfresj@co.cal.md.us

* Corresponding author.

Abstract:

The monospecific genera Eothyris (Petrolia Formation, Leonardian, Archer County, Texas) and Oedaleops (Abo/Cutler Formation, Wolfcampian, Rio Arriba County, New Mexico), known solely from cranial remains, are confidently assigned to the monophyletic Caseasauria based on cranial and dental characters. In addition, Eothyris and Oedaleops comprise the monophyletic Eothyrididae based on nine cranial and dental characters. In contrast to the medium to large sized herbivorous caseids, the small eothyridids exhibit dental features that indicate that they were faunivores. The presence of well-developed caniniform teeth suggests that they were predators. Both Eothyris parkeyi Romer and Oedaleops campi Langsten exhibit a suite of plesiomorphic cranial characters that identify them as basal synapsids. Thus, the eothyridids are better representatives of the primitive synapsid cranial morphotype than the oftenused ophiacodontids. Although they appear relatively late in synapsid evolution, both eothyridids are significantly older than all other caseasaurs, forcing the establishment of a long unrecorded lineage for caseids.

No time to comment. Link to paper in title.

Did Dimetrodon Piscovore?

Go Look at Beyond Bones.

The Great Bloom of Texas

So is this the future of a climate change? Texas gone green?