Patrick M O'Connor

Ohio University · Department of Biomedical Sciences

In amniotes, the predominant developmental strategy underlying body size evolution is thought to be adjustments to the rate of growth rather than its duration. However, most theoretical and experimental studies supporting this axiom focus on pairwise comparisons and/or lack an explicit phylogenetic framework. We present the first large-scale phylog...

Objective: Many patients with acromegaly, a hormonal disorder with excessive growth hormone (GH), report pain in joints. The objective of this study is to characterize the joint pathology of mice with over-expression of either bovine GH (bGH) or a GH receptor antagonist (GHa). We also investigate the effect of GH on regulation of chondrocyte cellu...

Postcranial skeletal pneumaticity, air‐filled bones of the trunk and limbs, is exclusive to birds among extant tetrapods and exhibits significant variation in its expression among different species. Such variation is not random but exhibits relationships with both body mass and locomotor specializations. Most species‐level comparative research to d...

A second K/Pg boundary interval in the northern sector of the Antarctic Peninsula on Vega Island has been proposed, yet current temporal resolution of these strata prohibits direct testing of this hypothesis. To not only test for the existence of a K/Pg boundary on Vega Island but also provide increased age resolution for the associated vertebrate...

The Western Branch of the East African Rift System has experienced multiple episodes of basin development and intraplate alkaline volcanism since the Jurassic, however the geodynamic processes and lithospheric evolution involved in this protracted geological history remains poorly defined. Here, we present SmNd, LuHf, and RbSr isotopic data of igne...

Numerous non-avian theropod dinosaur fossils have been reported from the Upper Cretaceous (Cenomanian) Bahariya Formation, Bahariya Oasis, Western Desert of Egypt, but unambiguous materials of Abelisauridae have yet to be documented. Here we report Mansoura University Vertebrate Paleontology Center (MUVP) specimen 477, an isolated, well-preserved t...

This study presents the first African pedogenic carbonate estimated atmospheric CO2 concentrations for the Early to Late Cretaceous transition. Pedogenic carbonates have been used extensively as proxies to reconstruct past climates, yet few studies have focused on the climatic conditions of Africa during the Mesozoic. The paucity of paleoclimate da...

The ability to accurately and reliably estimate body mass of extinct taxa is a vital tool for interpreting the physiology and even behavior of long-dead animals. For this reason, paleontologists have developed many possible methods of estimating the body mass of extinct animals, with varying degrees of success. These methods can be divided into two...

The fossil record of macroscelidean mammals is notoriously patchy, with a significant spatial and temporal gap separating faunas from the early Oligocene localities of northern Africa and the early Miocene localities of eastern and southern Africa. Here we describe fossil macroscelideans representing Myohyracinae and Rhynchocyoninae recovered from...

The Cretaceous Period is considered the archetypical greenhouse interval, yet there is mounting evidence for intermittent cooler climatic phases throughout this geologic span. Few continental climate histories exist for the Cretaceous south of the paleoequator, and fewer still for Africa during this time. The Cretaceous Galula Formation is one of t...

Postcranial skeletal pneumaticity (i.e., epithelial-lined, air-filled bones) is a condition unique to birds among extant tetrapods. Previous research reveals extensive variation in the expression of this trait in different bird species, from taxa that pneumatize nearly the entire skeleton to others that do not pneumatize a single bone. These studie...

Upper Cretaceous dinosaur remains from Afro-Arabia are rare and mainly restricted to pre-Turonian horizons. Consequently, the discovery of new fossils from Upper Cretaceous deposits in the Western Desert, central Egypt is significant because it adds to the meager record of dinosaurs described from this landmass. The oases of Kharga and Dakhla, West...

Mesozoic birds display considerable diversity in size, flight adaptations and feather organization1–4, but exhibit relatively conserved patterns of beak shape and development5–7. Although Neornithine (that is, crown group) birds also exhibit constraint on facial development8,9, they have comparatively diverse beak morphologies associated with a ran...

Extant snake faunas have their origins in the mid-Cenozoic, when colubroids replaced booid-grade snakes as the dominant species. Based on fossils from North America and Europe, the timing of this faunal changeover is thought to have occurred in the early Neogene, after a period of global cooling opened environments suitable for more active predator...

Lungfish (Dipnoi) date back to the Devonian, and some fossil taxa as well as extant African lungfishes are known for their ability to aestivate, tolerating low-oxygen environments associated with seasonal drying. Extant lungfish are separated into two families: Lepidosirenidae (Protopterus in Africa and Lepidosiren in South America) and Neoceratodo...

Upper Cretaceous (Campanian) deposits of the Quseir Formation exposed in the New Valley, Western Desert of Egypt have yielded abundant remains of bony and cartilaginous fishes, turtles, and non-marine archosaurs, of which crocodyliforms are among the best represented. Here we report a new crocodyliform from the El Hindaw Member of the Quseir Fm. fr...

Although knowledge of Mesozoic marine reptiles from Antarctica has improved considerably in recent years, associated and well-preserved skeletal material of these animals remains uncommon. Here we describe a largely complete, closely associated plesiosaur pelvic girdle recovered from the uppermost Cretaceous (Maastrichtian) Sandwich Bluff Member of...

Research in the Upper Cretaceous (Maastrichtian) Maevarano Formation of northwestern Madagascar has yielded numerous individuals of the abelisaurid theropod Majungasaurus crenatissimus. The number of individuals and quality of preservation allow for a detailed assessment of pathology in this species. A previous survey of Majungasaurus material coll...

We demonstrate an integrated methodology for using CT in both mechanical and digital preparation of field jackets collected at the MAD05-42 locality in Upper Cretaceous deposits from the Mahajanga Basin of Madagascar. Following detailed in-quarry mapping, intact field jackets were documented in a medical CT scanner to identify contents and spatial...

[This corrects the article DOI: 10.1371/journal.pone.0224734.].

Tooth replacement rate is an important contributor to feeding ecology for polyphyodont animals. Dinosaurs exhibit a wide range of tooth replacement rates, mirroring their diverse craniofacial specializations, but little is known about broad-scale allometric or evolutionary patterns within the group. In the current broad but sparse dinosaurian sampl...

Cape Marsh, located on the eastern end of Robertson Island to the east of the Antarctic Peninsula, exposes an isolated outcrop of Late Cretaceous sedimentary strata. The outcrop is approximately 120 km southwest of the much better-studied exposures of similar age on and around James Ross Island (JRI); as such, its remoteness has complicated both lo...

We demonstrate an integrated methodology for using CT in both mechanical and digital preparation of field jackets collected from locality MAD 05-42 in Upper Cretaceous deposits of the Maevarano Formation, Mahajanga Basin, Madagascar. Following in-quarry surface mapping, field jackets were documented in a medical CT scanner before mechanical prepara...

Although the fossil record of non-avian dinosaurs from the Cretaceous of Antarctica is the poorest of any continent, fossils representing at least five major taxonomic groups (Ankylosauria, early-diverging Ornithopoda, Hadrosauridae, Titanosauria, and Theropoda) have been recovered. All come from Upper Cretaceous (Coniacian–Maastrichtian) marine an...

In 2006, a partial avian femur (South Dakota School of Mines and Technology (SDSM) 78247) from the Upper Cretaceous (Maastrichtian) Sandwich Bluff Member of the López de Bertodano Formation of Sandwich Bluff on Vega Island of the northern Antarctic Peninsula was briefly reported as that of a cariamiform-a clade that includes extant and volant South...

The Mesozoic plate tectonic and paleogeographic history of Gondwana had a profound effect on the distribution of terrestrial vertebrates. As the supercontinent fragmented into a series of large landmasses (South America, Africa-Arabia, Antarctica, Australia, New Zealand, the Indian subcontinent, and Madagascar), particularly during the Late Jurassi...

Complex structures, like the vertebrate skull, are composed of numerous elements or traits that must develop and evolve in a coordinated manner to achieve multiple functions. The strength of association among phenotypic traits (i.e., integration), and their organization into highly-correlated, semi-independent subunits termed modules, is a result o...

We relay the circumstances of discovery leading to, and the subsequent mechanical and digital preparation of, the holotype and only known specimen of Vintana sertichi, the cranium of a gondwanatherian mammal from the Kinkony Member of the Late Cretaceous Maeverano Formation. While the specimen was collected in 2010 within a large sample from an unu...

We here establish a new mammaliaform genus and species, Galulatherium jenkinsi (Mammalia), from the Upper Cretaceous Galula Formation in the Rukwa Rift Basin of southwestern Tanzania. This represents the first named taxon of a mammaliaform from the entire Late Cretaceous of continental Afro-Arabia, an interval of 34 million years. Preliminary study...

The African terrestrial fossil record has been limited in its contribution to our understanding of both regional and global Cretaceous paleobiogeography, an interval of significant geologic and macroevolutionary change. A common component in Cretaceous African faunas, titanosaurian sauropods diversified into one of the most specious groups of dinos...

Bayesian nexus file. (NEX)

Parsimony nexus file. (NEX)

Bayesian equal rates tree file. (TRE)

Tip dating variable rates tree file. (TREE)

Bayesian variable rates tree file. (TRE)

Tip dating equal rates tree file. (TREE)

Supporting information. Supporting information containing the data used for phylogenetic analyses (taxa, stratigraphic ages, morphological character list and states, character modifications, and references). (DOCX)

Parsimony tree file. (TRE)

Non-marine vertebrates, including many crocodyliform clades, remain poorly documented from uppermost Cretaceous deposits of Africa. Recent exploratory fieldwork in the Upper Cretaceous (middle Campanian) Quseir Formation exposed around Dakhla Oasis (Western Desert of Egypt) has revealed new fossils from continental and marginal marine settings that...

Prominent hypotheses advanced over the past two decades have sought to characterize the Late Cretaceous continental vertebrate palaeobiogeography of Gondwanan landmasses, but have proved difficult to test because terrestrial vertebrates from the final ~30 million years of the Mesozoic are extremely rare and fragmentary on continental Africa (includ...

This study uses magnetostratigraphy to help constrain the age of the paleontologically important Galula Formation (Rukwa Rift Basin, southwestern Tanzania). The formation preserves a Cretaceous vertebrate fauna, including saurischian dinosaurs, a putative gondwanatherian mammal, and notosuchian crocodyliforms. With better dating, the Galula Formati...

Fragmentary cervical vertebral elements of a gigantic pterosaur are described from the upper Campanian-Maastrichtian Nemegt Formation in the Gobi Desert. With an estimated width of a posterior centrum across the postexapophyses of 198 mm, this taxon represents one of the largest pterosaurs currently known. This is the first discovery of a pterosaur...

Fragmentary cervical vertebral elements of a gigantic pterosaur are described from the upper Campanian–Maastrichtian Nemegt Formation in the Gobi Desert. With an estimated width of a posterior centrum across the postexapophyses of 198 mm, this taxon represents one of the largest pterosaurs currently known. This is the first discovery of a pterosaur...

The neopterygian fish Enchodus was a widespread, speciose genus consisting of approximately 30 recognized species that were temporally distributed from the late Early Cretaceous through the Paleocene. Many Enchodus specimens are fragmentary cranial remains or isolated dental elements, as is the case for previously reported occurrences in Egypt. Her...

The paleobiogeographic significance of continental Africa during the middle and Late Cretaceous is not well understood, in part due to incomplete sampling from large portions of the landmass during these intervals. Intensified field efforts in the Galula Formation exposed in southwestern Tanzania have revealed a diverse vertebrate fauna, including...

This paper presents a detailed sedimentologic investigation of a newly identified, fossiliferous Late Neogene sedimentary succession in the Rukwa Rift Basin, southwestern Tanzania. This synrift deposit is a rare and significant new example of a fossiliferous succession of this age in the Western Branch of East Africa Rift System. The unit, informal...

Precise dating and correlation of drilled wells through continental successions is challenging for hydrocarbon exploration, especially where preservation and recovery of age-diagnostic fossils is poor. As a complement or alternative to biostratigraphic dating we demonstrate the effectiveness of U–Pb geochronology via laser ablation–inductively coup...

Non-marine vertebrate fossils, including many crocodyliform clades, remain poorly documented from the upper-mostCretaceous deposits of Afro-Arabia. Recent exploratory fieldwork in the Upper Cretaceous (middle Campanian) Qusier Formation of the Dakhla and Kharga Oases in the Western Desert of Egypt hasrevealed tantalizing new fossils from continenta...

Late Cretaceous dinosaur remains from the Afro-Arabian continent are rare and mainly restricted to pre-Turonian horizons. Consequently, the discovery of new fossils from Upper Campanian (~73 Ma) deposits in the Western Desert, southern Egypt is very significant because it constitutes some of the first identifiable dinosaur material described from A...

A discovery of the sound-producing vocal organ known as the syrinx in a bird fossil from the end of the 'age of dinosaurs' highlights the anatomical basis for myriad aspects of avian social and behavioural evolution. See Letter p.502

Based on molecular dating, the origin of insect agriculture is hypothesized to have taken place independently in three clades of fungus-farming insects: the termites, ants or ambrosia beetles during the Paleogene (66-24 Ma). Yet, definitive fossil evidence of fungus-growing behavior has been elusive, with no unequivocal records prior to the late Mi...

Abelisaurid theropods were one of the most diverse groups of predatory dinosaurs in Gondwana during the Cretaceous. The group is characterized by a tall, wide skull and robust cervical region. This morphology is thought to have facilitated specialized feeding behaviors such as prolonged contact with prey. The Late Cretaceous abelisaurid Majungasaur...

The Upper Cretaceous (middle-late Campanian) Wahweap Formation of southern Utah contains the oldest diagnostic evidence of ceratopsids (to date, all centrosaurines) in North America, with a number of specimens recovered from throughout a unit that spans between 81 and 77 Ma. Only a single specimen has been formally named, Diabloceratops eatoni, fro...

Appendix C: Parameter setting used in MrBayes. (DOCX)

Appendix A: Specific specimen sources used for character scoring. (DOCX)

Character-taxon matrix for phylogenetic analysis. (DOCX)

Appendix B: Character list used for phylogenetic analysis. (DOCX)

Resultant 50% majority rule consensus tree from the parsimony analysis. Results of the maximum parsimony analysis reported here as the 50% majority rule consensus of 1194 most parsimonious trees (tree length = 160, CI = 0.675, RI, 0.818, RCI = 0.552) of an analysis of 101 characters arrayed across 26 ceratopsian taxa. Numbers in node boxes indicate...

3D-PDF of the braincase of Machairoceratops cronusi (UMNH VP 20550) gen. et sp. nov., based on CT scan data in S5 File. (PDF)

Recentmodel-based phylogenetic approaches have expanded upon the incorporation of extinct lineages and their respective temporal information for calibrating divergence date estimates. Here, model-based methods are explored to estimate divergence dates and ancestral ranges for titanosaurian sauropod dinosaurs, an extinct and globally distributed ter...

The Campanian and Maastrichtian stages are very poorly documented time intervals in Africa’s record of terrestrial vertebrate evolution. Upper Cretaceous deposits exposed in southern Egypt, near the Dakhla and Kharga Oases in the Western Desert, preserve abundant vertebrate fossils in nearshore marine environments, but have not yet been the focus o...

Sexual selection can influence the evolution of sexually dimorphic exaggerated display structures. Herein, we explore whether such costly ornamental integumentary structures evolve independently or if they are correlated with phenotypic change in the associated skeletal system. In birds, elongate tail feathers have frequently evolved in males and a...

We present the first digital reconstruction of the endocranial cavity and endosseous labyrinth of the Late Cretaceous gondwanatherian mammal Vintana sertichi from the Maevarano Formation of Madagascar. The Malagasy specimen is exceptionally well preserved and represents the only described cranium known for Gondwanatheria, an enigmatic clade from th...

The Gondwanatheria are an enigmatic clade of Cretaceous and Paleogene mammals known from South America, Africa, Madagascar, India, and the Antarctic Peninsula. The eight valid species-each belonging to a monotypic genus and the first of which was described only 30years ago-are represented almost exclusively by isolated teeth, in addition to fragmen...

ABSTRACT-Living mammals are distinguished from other extant tetrapods by adaptations for improved senses of hearing, touch, and smell. These adaptations, and concomitant reductions in visual anatomy, evolved during the Mesozoic in the mammalian and therian stem lineages. Here, we present a comparative study of the sensory anatomy of the Late Cretac...

Previously known only from isolated teeth and lower jaw fragments recovered from the Cretaceous and Palaeogene of the Southern Hemisphere, the Gondwanatheria constitute the most poorly known of all major mammaliaform radiations. Here we report the discovery of the first skull material of a gondwanatherian, a complete and well-preserved cranium from...