Histological, chemical, and morphological reexamination of the “heart” of a small Late Cretaceous Thescelosaurus

  title={Histological, chemical, and morphological reexamination of the “heart” of a small Late Cretaceous Thescelosaurus},
  author={Timothy P. Cleland and Michael K. Stoskopf and Mary Higby Schweitzer},
A three-dimensional, iron-cemented structure found in the anterior thoracic cavity of articulated Thescelosaurus skeletal remains was hypothesized to be the fossilized remains of the animal’s four-chambered heart. This was important because the finding could be interpreted to support a hypothesis that non-avian dinosaurs were endothermic. Mammals and birds, the only extant organisms with four-chambered hearts and single aortae, are endotherms. The hypothesis that this Thescelosaurus has a… Expand
The cranial anatomy of the neornithischian dinosaur Thescelosaurus neglectus
The new morphological observations presented herein, combined with re-examination of the holotype of Parksosaurus, suggest that Parksosaurus shares a closer relationship with Thescelosaurus than with Gasparinisaura, and that many of the features previously cited to support a relationship with the latter taxon are either also present in Thes Celosaurus, are artifacts of preservation, or are the result of incomplete preparation and inaccurate interpretation of specimens. Expand
Heart fossilization is possible and informs the evolution of cardiac outflow tract in vertebrates
It is demonstrated that cardiac preservation is possible in the extinct fish Rhacolepis buccalis from the Brazilian Cretaceous and suggested that outflow tract simplification in actinopterygians is compatible with a gradual, rather than a drastic saltation event. Expand
Expansion for the Brachylophosaurus canadensis Collagen I Sequence and Additional Evidence of the Preservation of Cretaceous Protein.
The data robustly support the hypothesis of an endogenous origin for these peptides, confirm the idea that peptides can survive in specimens tens of millions of years old, and bolster the validity of the 2009 study. Expand
Microbes and the Fossil Record: Selected Topics in Paleomicrobiology
Studies of the microbial fossil record are relevant to profound, perennial questions that have puzzled humanity and science—they provide the only direct window onto the beginnings and early evolution of life; and the methods and criteria developed for recognizing ancient, inconspicuous traces oflife have yielded an approach directly applicable to the search for traces of life on other worlds. Expand
Comparative cardiovascular physiology: future trends, opportunities and challenges
A focused workshop comprising comparative cardiovascular physiologists to ponder some of the key unanswered questions in the field, centred around three themes which involved poorly understood aspects of the interaction of the cardiovascular system with the lymphatic, renal and digestive systems. Expand
Getting to the heart of a good fossil
The discovery of perfectly preserved 113-119 million year old fossilised hearts in a Brazilian fish Rhacolepis has significant implications for palaeontology and comparative anatomy.
Trust in Technicians in Paleontology Laboratories
New technologies can upset scientific workplaces’ established practices and social order. Scientists may therefore prefer preserving skilled manual work and the social status quo to revolutionaryExpand
Can ovarian follicles fossilize?
Ovary follicles in three fossil birds from the Early Cretaceous period of China belonging to Jeholornis and two enantiornithine species are described, but the morphology of the fossil structures does not agree with the ovulation mode of coelurosaurs. Expand
Can ovarian follicles fossilize
Ovary follicles in three fossil birds from the Early Cretaceous period of China belonging to Jeholornis and two enantiornithine species are described, but the morphology of the fossil structures does not agree with the ovulation mode of coelurosaurs. Expand
Stable isotopic characterization of a coastal floodplain forest community: a case study for isotopic reconstruction of Mesozoic vertebrate assemblages
A critical isotopic baseline for coastal floodplain forests is provided, and a modified oxygen isotope-temperature equation that uses mean endotherm and mean ectotherm isotope data to more precisely predict temperature when compared with measured Atchafalaya River water data is proposed. Expand


Reinterpretation of a remarkably well preserved pterosaur soft tissue from the Early Cretaceous of Brazil
SEM analysis shows that there is no duplication of any layer and that structural fibers are absent, contrary to what would be expected in a transverse section of wing membrane, which suggests that the soft tissue is part of the integument near the shoulder girdle and thorax, and is not part of a soft tissue primarily involved in flight. Expand
Exceptional soft-tissue preservation in a theropod dinosaur from Italy
The Lower Cretaceous Pietraroia Plattenkalk (Benevento Province, southern Italy) has been known since the eighteenth century for its beautifully preserved fossil fishes. During Albian time (about 113Expand
Comparative cardiac anatomy of the reptilia. III. The heart of crocodilians and an hypothesis on the completion of the interventricular septum of crocodilians and birds
  • G. Webb
  • Biology, Medicine
  • Journal of morphology
  • 1979
The crocodilian heart is compared with, and seen as an advancement of, the heart of non‐crocodilian reptiles, and the varanid ventricle is re‐examined, as it appeared to contain many crocodilian features, along with the ophidian characteristics described previously. Expand
Soft Tissue Preservation in Terrestrial Mesozoic Vertebrates
Exceptionally preserved fossils—i.e., those that retain, in some manner, labile components of organisms that are normally degraded far too quickly to enter the fossil record—hold the greatestExpand
Evidence for Endothermic Ancestors of Crocodiles at the Stem of Archosaur Evolution
Developmental studies show that all of these uniquely crocodilian features are secondarily derived, indicating a shift from the complete separation of blood flow of endotherms to the controlled shunting of ectotherms. Expand
The Chemical and Microbial Degradation of Bones and Teeth
The physical survival of bone is integral to any kind of palaeopathological study. Not only must the skeleton survive in the burial environment or tomb, it must retain sufficient strength to beExpand
Functional Morphology in Vertebrate Paleontology
This paper presents a meta-analysis of the evolution of the hindlimb and tail from basal theropods to birds and the consequences of skull flattening in crocodilians and an analysis of the posture and gait of ceratopsian dinosaurs. Expand
Although the embryonic skin does not show definitive evidence of armor, the posthatching development of osteoderms cannot be ruled out, and a variety of scale patterns previously unknown for the skin of these animals is reported. Expand
The 'dermal armour' of the ornithopod dinosaur Hypsilophodon from the Wealden (Early Cretaceous: Barremian) of the Isle of Wight: a reappraisal
Abstract The small ornithopod dinosaur Hypsilophodon foxii , from the Early Cretaceous (Barremian) of the Isle of Wight, England, is one of the best known of all dinosaurs; however, the reportedExpand
Taxonomic Revison of the Basal Neornithischian Taxa Thescelosaurus and Bugenasaura
This analysis is the first to recover a clade containing all basal neornithischian taxa from the Cretaceous of North America, within which P. warreni is recovered as the sister taxon to a Thescelosaurus clade whose monophyly is supported by five cranial autapomorphies. Expand