Matthew Lamanna

• PhD
• Mary R. Dawson Curator at Carnegie Museum Of Natural History

We describe a giant titanosaurid sauropod dinosaur discovered in coastal deposits in the Upper Cretaceous Bahariya Formation of Egypt, a unit that has produced three Tyrannosaurus-sized theropods and numerous other vertebrate taxa. Paralititan stromeri is the first tetrapod reported from Bahariya since 1935. Its 1.69-meter-long humerus is longer th...

The oviraptorosaurian theropod dinosaur clade Caenagnathidae has long been enigmatic due to the incomplete nature of nearly all described fossils. Here we describe Anzu wyliei gen. et sp. nov., a new taxon of large-bodied caenagnathid based primarily on three well-preserved partial skeletons. The specimens were recovered from the uppermost Cretaceo...

Titanosaurian sauropod dinosaurs were the most diverse and abundant large-bodied herbivores in the southern continents during the final 30 million years of the Mesozoic Era. Several titanosaur species are regarded as the most massive land-living animals yet discovered; nevertheless, nearly all of these giant titanosaurs are known only from very inc...

We describe Sarmientosaurus musacchioi gen. et sp. nov., a titanosaurian sauropod dinosaur from the Upper Cretaceous (Cenomanian-Turonian) Lower Member of the Bajo Barreal Formation of southern Chubut Province in central Patagonia, Argentina. The holotypic and only known specimen consists of an articulated, virtually complete skull and part of the...

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...

Fossils representing Cretaceous lineages of crown clade birds (Aves) are exceptionally rare but are crucial to elucidating major ecological shifts across early avian divergences. Among the earliest known putative crown birds is Vegavis iaai1, 2, 3, 4–5, a foot-propelled diver from the latest Cretaceous (69.2–68.4 million years ago)⁶ of Antarctica w...

Megaraptorans are medium- to large-bodied tetanuran theropod dinosaurs known from Cretaceous deposits in Asia, Australia, and especially South America. The megaraptoran skeleton is far from well known, and the humerus is one of the least-frequently preserved elements. Here we describe the first-documented adult humerus of a South American megarapto...

Unenlagiine paravians are among the most relevant Gondwanan theropod dinosaur clades for understanding the origin of birds, yet their fossil record remains incomplete, with most taxa being represented by fragmentary material and/or separated by lengthy temporal gaps, frustrating attempts to characterize unenlagiine evolution. Here we describe Diuqi...

Dinosaur fossils from the latest Cretaceous (Campanian–Maastrichtian) of Africa and the Arabian Peninsula are rare. Most discoveries to date have consisted of limited fossils that have precluded detailed phylogenetic and paleobiogeographic interpretations. Fortunately, recent discoveries such as the informative Egyptian titanosaurian sauropod dinos...

Megaraptora is a group of enigmatic, carnivorous non‐avian theropod dinosaurs from the Cretaceous of Asia, Australia, and especially South America. Perhaps the most striking aspect of megaraptoran morphology is the large, robustly constructed forelimb that, in derived members of the clade, terminates in a greatly enlarged manus with hypertrophied,...

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...

Myhrvold et al. suggest that our inference of subaqueous foraging among spinosaurids is undermined by selective bone sampling, inadequate statistical procedures, and use of inaccurate ecological categorizations. Myhrvold et al. ignore major details of our analyses and results, and instead choose to portray our inferences as if they were based on qu...

Secondary aquatic adaptations evolved independently more than 30 times from terrestrial vertebrate ancestors1,2. For decades, non-avian dinosaurs were believed to be an exception to this pattern. Only a few species have been hypothesized to be partly or predominantly aquatic3–11. However, these hypotheses remain controversial12,13, largely owing to...

We describe six specimens consisting of cranial remains and associated partial presacral axial series belonging to ornithuromorph birds from the Changma locality of the Lower Cretaceous Xiagou Formation of northwestern Gansu Province, China. Comparison among specimens is limited by the paucity of overlapping elements, their differing exposed views,...

We describe and incorporate fragmentary new cranial and postcranial materials of hadrosaurid ornithopods into the non-avian dinosaur assemblage of the Upper Cretaceous (Coniacian–Maastrichtian) Lago Colhué Huapi Formation of central Patagonia, south-central Chubut Province, Argentina. The fossils come from the upper part of the formation, probably...

Xenotarsosaurus bonapartei was the third abelisaurid theropod dinosaur to be named from Argentina. The holotype comprises two partial anterior dorsal vertebrae and a complete right hind limb from the Upper Cretaceous (lower Cenomanian–upper Turonian) Bajo Barreal Formation, central Patagonia, Argentina. The materials display morphological features...

Recent studies demonstrate that many avialan features evolved incrementally prior to the origin of the group, but the presence of some of these features, such as bird-like brooding behaviours, remains contentious, in non-avialan dinosaurs. Here we report the first non-avialan dinosaur fossil known to preserve an adult skeleton atop an egg clutch th...

We describe two partial postcranial skeletons belonging to the enigmatic theropod dinosaur clade Megaraptoridae from the Upper Cretaceous (lower Cenomanian-upper Turonian) Bajo Barreal Formation of southern Chubut Province, central Patagonia, Argentina. The specimens are assigned to Megaraptoridae due to their possession of multiple anatomical feat...

Osteological correlates preserve more readily than their soft tissue counterparts in the fossil record; therefore, they can more often provide insight into the soft tissue anatomy of the organism. These insights can in turn elucidate the biology of these extinct organisms. In this study, we reconstruct the pelvic girdle and hind limb musculature of...

Sauropod dinosaurs from the post-Cenomanian Cretaceous (PCC; ~94–66 Ma) of continental Africa (excluding Madagascar) and the then-conjoined Arabian Peninsula are almost exclusively represented by isolated, poorly-informative fossils. One of the handful of exceptions in this regard is the lithostrotian titanosaur Mansourasaurus shahinae, recently id...

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...

Soft tissues are variably preserved in the fossil record with external tissues, such as skin and feathers, more frequently preserved than internal tissues (e.g. muscles). More commonly, soft tissues leave traces of their locations on bones and, for muscles, these clues can be used to reconstruct the musculature of extinct vertebrates, thereby enhan...

The middle-late Eocene of Antarctica was characterized by dramatic change as the continent became isolated from the other southern landmasses and the Antarctic Circumpolar Current formed. These events were crucial to the formation of the permanent Antarctic ice cap, affecting both regional and global climate change. Our best insight into how life i...

The Upper Jurassic Morrison Formation of the western United States preserves one of the best-known Mesozoic paleoecosystems worldwide. The formation crops out over an area from New Mexico and Oklahoma to Montana and Utah and encompasses a time span of approximately eight million years. Recent studies indicate a high diversity of gigantic, herbivoro...

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...

Abelisaurid theropods were the most diverse and abundant medium-sized to large-bodied carnivorous dinosaurs in many Gondwanan and European paleoecosystems during the Late Cretaceous, frequently occupying the apex predator niche in these environments. Although several derived abelisaurids (e.g., the Patagonian brachyrostrans Ekrixinatosaurus novasi,...

The Upper Cretaceous (Cenomanian) Bahariya Formation of the Bahariya Oasis in the Egyptian Western Desert has yielded a diverse fossil vertebrate assemblage, including the type specimens of the non-avian theropods Spinosaurus, Carcharodontosaurus, and Bahariasaurus, the titanosaurian sauropods Paralititan and Aegyptosaurus, and the crocodyliforms L...

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...

Peirosaurid crocodyliforms were diverse and abundant in the Cretaceous of the Gondwanan landmasses, especially South America. Here, we describe Colhuehuapisuchus lunai, gen. et sp. nov., a new peirosaurid taxon from the Upper Cretaceous (Campanian-?lower Maastrichtian) Lago Colhué Huapi Formation of southern Chubut Province in central Patagonia, Ar...

In the last two decades, the number of phylogenetically informative anatomical characters recognized in the appendicular skeleton of titanosaurian sauropod dinosaurs has increased dramatically with the discovery of new and comparatively complete specimens. here we provide an overview of the appendicular skeletal morphology of South American titanos...

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...

Understanding non-crown dinosaur reproduction is hindered by a paucity of directly associated adults with reproductive traces. Here we describe a new enantiornithine, Avimaia schweitzerae gen. et sp. nov., from the Lower Cretaceous Xiagou Formation with an unlaid egg two-dimensionally preserved within the abdominothoracic cavity. Ground-sections re...

Titanosaurs were the last-surviving group of sauropod dinosaurs, having persisted until the end-Cretaceous. Since the early 21st century, knowledge of this diverse and cosmopolitan group of dinosaurs has greatly improved, although many aspects of their biology and evolutionary history remain poorly understood. In particular, knowledge of Late Creta...

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...

We describe Tratayenia rosalesi gen. et sp. nov., a new megaraptoran theropod dinosaur from the Upper Cretaceous of Patagonia, Argentina. The holotype consists of a well-preserved, mostly articulated series of dorsal and sacral vertebrae, two partial dorsal ribs, much of the right ilium, and pubis and ischium fragments. It was found in a horizon of...

Many titanosaurian dinosaurs are known only from fragmentary remains, making comparisons between taxa difficult because they often lack overlapping skeletal elements. This problem is particularly pronounced for the exceptionally large-bodied members of this sauropod clade. Dreadnoughtus schrani is a well-preserved giant titanosaurian from the Upper...

Metatarsals of titanosaurian sauropod dinosaurs are rarely found, hindering understanding of their functional morphology and phylogenetic utility. Only a few titanosaurian taxa preserve a complete or even nearly complete metatarsus (e.g., Bonitasaura, Epachthosaurus, Notocolossus, Opisthocoelicaudia, Rapetosaurus). Here we reassess the metatarsus o...

Dinosaur fossils are extraordinarily rare from the latest Cretaceous (Campanian–Maastrichtian) of continental Africa and Arabia (Afro-Arabia), with the majority of finds consisting of isolated, fragmentary teeth and bones. Due to this lack of informative material, the phylogenetic and paleobiogeographic affinities of Campanian–Maastrichtian Afro-Ar...

We describe five partial middle and posterior dorsal vertebrae from an upper Kimmeridgian exposure of the Upper Jurassic Morrison Formation at the Carnegie Quarry of Dinosaur National Monument (Utah, USA), and refer these vertebrae to the poorly known diplodocid sauropod dinosaur genus Barosaurus Marsh, 1890. The small size and unfused neurocentral...

In dinosaurs and other archosaurs, the presence of foramina connected with internal chambers in axial and appendic-ular bones is regarded as a robust indicator of postcranial skeletal pneumaticity (PSP). Here we analyze PSP and its paleobiological implications in rebbachisaurid diplodocoid sauropod dinosaurs based primarily on the dorsal vertebrae...

A well preserved middle caudal vertebra from middle Cretaceous (?Albian–lower Cenomanian) deposits informally known as the “Kem Kem beds” exposed in the Gara Sbaa region of Morocco is attributed to a large-bodied titanosaurian sauropod dinosaur. It represents one of the best-preserved and most complete skeletal elements reported for this sauropod g...

Animation of horizontal computed tomographic (CT) images of cranium of Sarmientosaurus musacchioi gen. et sp. nov. (MDT-PV 2). Positions of CT images indicated by orange line in digital visualization of cranium in right lateral view. Scale bar = 5 cm. (MOV)

Animation of sagittal computed tomographic (CT) images of cranium of Sarmientosaurus musacchioi gen. et sp. nov. (MDT-PV 2). Positions of CT images indicated by orange line in digital visualization of cranium in dorsal view. Scale bar = 5 cm. (MOV)

Data matrix for second iteration of second (i.e., based on Zaher et al. [14]) phylogenetic analysis of Sarmientosaurus musacchioi gen. et sp. nov. (22 ingroup taxa, 246 characters). (NEX)

Data matrix for first iteration of first (i.e., 337 character) phylogenetic analysis of Sarmientosaurus musacchioi gen. et sp. nov. (22 ingroup taxa, 337 characters). (NEX)

Data matrix for second iteration of first (i.e., 337 character) phylogenetic analysis of Sarmientosaurus musacchioi gen. et sp. nov. (24 ingroup taxa, 337 characters). (NEX)

Data matrix for first iteration of second (i.e., based on Zaher et al. [14]) phylogenetic analysis of Sarmientosaurus musacchioi gen. et sp. nov. (31 ingroup taxa, 246 characters). (NEX)

Animation of axial computed tomographic (CT) images of cranium of Sarmientosaurus musacchioi gen. et sp. nov. (MDT-PV 2). Positions of CT images indicated by orange line in digital visualization of cranium in right lateral view. Scale bar = 5 cm. (MOV)

Animation of axial computed tomographic (CT) images of right (top) and left (bottom) mandibular rami of Sarmientosaurus musacchioi gen. et sp. nov. (MDT-PV 2). Positions of CT images indicated by orange line in digital visualizations of right and left mandibular rami in medial and lateral views, respectively. Scale bar = 5 cm. (MOV)

Animation of sagittal computed tomographic (CT) images of right (top) and left (bottom) mandibular rami of Sarmientosaurus musacchioi gen. et sp. nov. (MDT-PV 2). Positions of CT images indicated by orange line in digital visualizations of right and left mandibular rami in caudal view. Scale bar = 5 cm. (MOV)

Characters used in first (i.e., 337 character) phylogenetic analysis of Sarmientosaurus musacchioi gen. et sp. nov. (DOC)

Data matrix for third iteration of first (i.e., 337 character) phylogenetic analysis of Sarmientosaurus musacchioi gen. et sp. nov. (25 ingroup taxa, 295 characters). (NEX)

Data matrix for third iteration of second (i.e., based on Zaher et al. [14]) phylogenetic analysis of Sarmientosaurus musacchioi gen. et sp. nov. (23 ingroup taxa, 246 characters). (NEX)

Animation of horizontal computed tomographic (CT) images of right (top) and left (bottom) mandibular rami of Sarmientosaurus musacchioi gen. et sp. nov. (MDT-PV 2). Positions of CT images indicated by orange line in digital visualizations of right and left mandibular rami in medial and lateral views, respectively. Scale bar = 5 cm. (MOV)

Titanosauria is an exceptionally diverse, globally-distributed clade of sauropod dinosaurs that includes the largest known land animals. Knowledge of titanosaurian pedal structure is critical to understanding the stance and locomotion of these enormous herbivores and, by extension, gigantic terrestrial vertebrates as a whole. However, completely pr...

We provide a detailed description of a well-preserved enantiornithine specimen (GSGM-05-CM-004) from the Lower Cretaceous (Aptian) Xiagou Formation of northwestern Gansu Province, China, for which we erect the new taxon Feitianius paradisi, gen. et sp. nov. This specimen has a distinctive pelvic morphology and can be further distinguished from all...

The braincase from the Upper Jurassic (lower Tithonian) Morrison Formation of the Carnegie Quarry at Dinosaur National Monument (Utah), which was assigned to the ankylopollexian iguanodontian ornithopod dinosaur Uteodon aphanoecetes (Carpenter and Wilson, 2008) is actually that of the dryosaurid iguanodontian Dryosaurus cf. D. altus (Marsh, 1878)....

Supplementary Information

Due to their abundance, taxonomic and morphological diversity, wide range of body sizes and broad geographical distribution, titanosaurian sauropods were one of the most important Cretaceous herbivorous dinosaur groups. Consequently, titanosaurs constitute one of the best samples in which to evaluate the relationship between bony structures and unp...

Microbodies associated with fossil feathers, originally attributed to microbial biofilm, have been reinterpreted as melanosomes: pigment-containing, eukaryotic organelles. This interpretation generated hypotheses regarding coloration in non-avian and avian dinosaurs. Because melanosomes and microbes overlap in size, distribution and morphology, we...

Titanosauriform sauropod dinosaurs are widely regarded as the most diverse and abundant large herbivores in Cretaceous paleoecosystems of Gondwanan landmasses. Nevertheless, remains of these animals are scarce in Late Cretaceous deposits of continental Africa and the then-conjoined Arabian Peninsula. Here we describe two new titanosauriform fossils...

Cretaceous outcrops in southern South America preserve a rich and evolutionarily important record of sauropod dinosaurs. Among Sauropoda, South American titanosaurs have garnered particular interest due to their abundance and taxonomic diversity. Nevertheless, the fossil record of rebbachisaurids has also improved significantly in recent years, and...

We present an annotated and illustrated catalogue of all original fossils, casts, and sculpted replicas of pterosaur specimens from the Upper Jurassic Solnhofen limestones of southern Germany that are housed at Carnegie Museum of Natural History (Pittsburgh, Pennsylvania, U.S.A.). The museum obtained its substantial Solnhofen pterosaur fossil colle...

We describe Katepensaurus goicoecheai, gen. et sp. nov., a diplodocoid sauropod dinosaur from the Bajo Barreal Formation (Upper Cretaceous: Cenomanian–Turonian) of south-central Chubut Province, central Patagonia, Argentina. The holotypic specimen is a closely associated partial axial skeleton that includes cervical, dorsal, and caudal vertebrae. T...

We present a reinterpretation of the bones previously identified as ossified hyoid elements in the Asian Late Cretaceous ceratopsian dinosaur Protoceratops andrewsi Granger and Gregory, 1923. Comparisons with other ceratopsian skeletons indicate that the tetraradiate bone tentatively regarded as a first ceratobranchial is actually an incomplete mid...

A new genus of crab from the Late Cretaceous of Antarctica increases diversity within Necrocarcinidae Förster, 1968, and demonstrates what appear to be gradual evolution and sympatric speciation in the southern high latitudes. New taxa include Hadrocarcinus tectilacus, new genus, new species, as well as two new combinations, Hadrocarcinus carinatus...

A newly discovered osteichthyan ectopterygoid from the Upper Cretaceous (lower Cenomanian) Bahariya Formation of the Bahariya Oasis, Egypt, is nearly identical to the holotypic specimen of Polypterus? bartheli from the same area and geologic unit. The Bahariya ectopterygoids are referable to Polypteridae based on the presence of a robust, laterally...

The Albian-Cenomanian Alcantara Formation of northeastern Brazil preserves the most diverse continental vertebrate fauna of this age yet known from northern South America. The Alcantara vertebrate assemblage, consisting of elasmobranchs, actinopterygians, sarcopterygians, turtles, crocodyliforms, pterosaurs, and non-avian dinosaurs, displays close...