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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 the giant titanosaurian sauropod Dreadnoughtus schrani based on observations of osteological correlates and Extant Phylogenetic Bracket comparisons. Recovered fossils of Dreadnoughtus exhibit remarkably well‐preserved, well‐developed, and extensive muscle scars. Furthermore, this taxon is significantly larger bodied than any titanosaurian for which a myological reconstruction has previously been performed, rendering this contribution highly informative for the group. All 20 of the muscles investigated in this study are sufficiently well supported to enable reconstruction of at least one division, including reconstruction of the M. ischiocaudalis for the first time in a sauropod dinosaur. In total, 34 osteological correlates were identified on the pelvic girdle and hind limb remains of Dreadnoughtus, allowing the reconstruction of 14 muscles on the basis of Level I or Level II inferences (i.e., not Level I' or Level II' inferences). Comparisons among titanosaurians suggest widespread myological variation, yet potential phylogenetic and other paleobiologic patterns are often obscured by fragmentary preservation, infrequent myological studies, and lack of consensus on the phylogenetic placement of many taxa. However, a ventrolateral accessory process is present on the preacetabular lobe of the ilium in all of the largest titanosauriforms that preserve this skeletal element, suggesting that the presence of this process (representing the origin of the M. puboischiofemoralis internus part II) may be associated with extreme body size. By identifying such myological patterns among titanosauriforms, we can begin to address specific evolutionary and biomechanical questions related to their skeletal anatomy, how they were capable of leaving wide‐gauge trackways, and resulting locomotor attributes unique to this clade. [ABSTRACT FROM AUTHOR]

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 Cretaceous (Campanian-Maastrichtian) Cerro Fortaleza Formation of southern Patagonia, Argentina. Numerous skeletal elements are known for Dreadnoughtus, including seven nearly complete dorsal vertebrae and a partial dorsal neural arch that collectively represent most of the dorsal sequence. Here we build on our previous preliminary description of these skeletal elements by providing a detailed assessment of their serial positional assignments, as well as comparisons of the dorsal vertebrae of Dreadnoughtus with those of other exceptionally large-bodied titanosaurians. Although the dorsal elements of Dreadnoughtus probably belong to two individuals, they exhibit substantial morphological variation that suggests that there is minimal, if any, positional overlap among them. Dreadnoughtus therefore preserves the second-most complete dorsal vertebral series known for a giant titanosaurian that has been described in detail, behind only that of Futalognkosaurus. The dorsal sequence of Dreadnoughtus provides valuable insight into serial variation along the vertebral column of these enormous sauropods. Such variation includes the variable presence of divided spinodiapophyseal laminae and associated spinodiapophyseal fossae. Given that dorsal vertebrae are the only elements that overlap between known remains of most giant titanosaurian taxa, the dorsal series of Dreadnoughtus provides a means to directly compare the morphologies of these sauropods. The dorsal vertebrae of Dreadnoughtus and Futalognkosaurus have dorsoventrally narrow transverse processes, unlike the condition in Puertasaurus. Further, Dreadnoughtus and Argentinosaurus have ventromedially inclined prezygapophyses, whereas Futalognkosaurus has almost horizontal prezygapophyses. The continued inclusion of new, well-represented skeletons of titanosaurians such as Dreadnoughtus in phylogenetic and functional morphological studies will aid in deciphering the interrelationships and paleobiology of Titanosauria. [ABSTRACT FROM AUTHOR]

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 unpreserved soft-tissues within Sauropoda. We reconstruct the morphology and interpret the implications of selected soft-tissues associated with the titanosaurian caudal skeleton. These tissues, especially the M. caudofemoralis longus (CFL), exerted a considerable influence on the anatomy of the caudal vertebrae and haemal arches. In all studied titanosaurian taxa, the reconstructed caudofemoral musculature corresponds to one of three principal morphotypes that accord with previously recognised phylogenetic patterns within the clade. Basal titanosaurians had an elongate M. CFL that extended for much of the proximal half of the tail; in saltasaurines, this muscle was much shorter. Non-saltasaurine lithostrotians exhibited an intermediate condition. Furthermore, the differing position of the fourth trochanter, and therefore, the insertion of the caudofemoral muscles, among various titanosaurian taxa suggests distinctions in the locomotor function of these animals. [ABSTRACT FROM AUTHOR]

Remains of the aulopiform bony fish Enchodus are very often the most common vertebrate fossils recovered from Late Cretaceous marine deposits around the world, especially in North America. Yet, those remains rarely consist of anything other than isolated dermopalatine bones and teeth. Here we report the discovery of an exceptionally well-preserved Enchodus ferox skull in a phosphatic concretion from the lower Ripley Formation (lower Maastrichtian) of Alabama. The specimen is significant because it preserves most of the cranial elements in their original, articulated positions. The specimen reveals characteristics that appear to be common to the genus including a robust skull with massive preoperculars and maxillae, large metapterygoids, fusion of the dentaries to the articulars, and paired sclerotic rings. The enlarged dermopalatine bones and "fangs" are not visible, but are likely preserved within the concretion, suggesting that they may be positioned more medially and posteriorly in the oral cavity than is sometimes depicted. The morphology suggests a specialized feeding behavior and prey, with the enlarged dermopalatine and mandible teeth being well adapted for piercing, holding, and aligning straight cephalopods for most efficient ingestion. [ABSTRACT FROM AUTHOR]

Brachyuran decapods (crabs) are rarely preserved in coastal environments and have not been documented in close association with dinosaur fossils. A crab referable to the Necrocarcinidae Förster, 1968, is here described from the Cenomanian Bahariya Formation, Bahariya Oasis, Egypt. The occurrence of a crab in a mangrove setting in association with terrestrial vertebrates is extremely unusual in the fossil record. Review of decapod occurrences from the region has resulted in placement of Portunus sp. of Roger (1946) within the Raninidae de Haan, 1839, and Lophoraninella cretacea (Dames, 1886) into the Galatheoidea Samouelle, 1819. The crabs of the Bahariya Formation were probably scavengers, feeding on vegetation and other organic material and were possibly a food source for fish and other vertebrates and invertebrates in the environment. [ABSTRACT FROM AUTHOR]

Three-dimensional specimens of the volant fossil bird Gansus yumenensis from the Early Cretaceous Xiagou Formation of northwestern China demonstrate that this taxon possesses advanced anatomical features previously known only in Late Cretaceous and Cenozoic ornithuran birds. Phylogenetic analysis recovers Gansus within the Ornithurae, making it the oldest known member of the clade. The Xiagou Formation preserves the oldest known ornithuromorph-dominated avian assemblage. The anatomy of Gansus, like that of other non-neornithean (nonmodern) ornithuran birds, indicates specialization for an amphibious life-style, supporting the hypothesis that modern birds originated in aquatic or littoral niches. [ABSTRACT FROM AUTHOR]