Growth and life history of Middle Miocene deer (Mammalia, Cervidae) based on bone histology

ABSTRACT Coprolites are a useful tool to obtain information related to the life history of the producer, trophic interactions, biodiversity, paleoenvironments, and paleoclimate, among other issues. We analyze here a sample of 111 coprolites recovered from levels of the Santa Cruz Formation (lower–middle Miocene, Burdigalian–early Langhian), outcropping in different localities of the Santa Cruz Province, Patagonian Argentina. Based on size and shape, two morphotypes were identified: coprolites assigned to morphotype I vary from ovoid to subspherical in shape, while coprolites assigned to morphotype II are cylindrical in shape. Several coprolites have bone and teeth inclusions belonging to small mammals (i.e., Octodontoidea and/or Chinchilloidea rodents). Morphometry, composition, and taphonomy of the bone remains suggest that the coprolites were produced by carnivorous mammals. According to the features of the guild of carnivorous mammals from the Santa Cruz Formation, we interpret that hathliacynids and/or small borhyaenoids (Sparassodonta) are the most probable producers. Different traces recorded in the coprolites, such as borings and putative eggs, suggest that the feces were exploited by coprophagous insects, probably dung beetles, for different purposes such as feeding and possible oviposition.

Download Full-text

Life history of Tendaguru sauropods as inferred from long bone histology

Fossil Record ◽

10.1002/mmng.1999.4860020107 ◽

1999 ◽

Vol 2 (1) ◽

pp. 103-112 ◽

Cited By ~ 12

Author(s):

P. M. Sander

Keyword(s):

Life History ◽

Body Size ◽

Sexual Dimorphism ◽

Sexual Maturity ◽

Upper Jurassic ◽

Bone Histology ◽

Long Bone ◽

Large Mammals ◽

Growth Series ◽

History Of

Abstract. Sauropod dinosaurs present exceptional challenges in understanding their biology because of their exceptional body size. One of these, life history, can be inferred from the histology of their bones. For this purpose, the diverse sauropod assemblage of the Upper Jurassic Tendaguru beds was sampled with a new coring method which provided unprecented access to and insights into sauropod bone histology. Growth series of humeri and femora as well as long growth records from single bones suggest that all four sauropod taxa are characterized by continued growth after sexual maturity but that growth was determinate. Fibrolamellär bone is dominant in the samples, indicating that the bones of the Tendaguru sauropods grew at rates comparable to those of modern large mammals. The growth pattern of these sauropods thus combines typically reptilian traits with typically mammalian traits. In the details of their bone histology, the Tendaguru sauropod taxa show considerable variation which reflects life history. In addition, Barosaurus exhibits probable sexual dimorphism in bone histology. Das Verständnis der Biologie der sauropoden Dinosaurier wird durch ihre enorme Körpergröße außerordentlich erschwert. Allerdings kann ein Aspekt, die Lebensgeschichte, anhand der Histologie ihrer Knochen untersucht werden. Zu diesem Zweck wurde die diverse Sauropoden-Vergesellschaftung der oberjurassischen Tendaguru-Schichten beprobt, und zwar mit einer neuartigen Kernbohrmethode, die einen herausragenden Zugang und Einblick in die Knochenhistologie der Sauropoden ermöglichte. Wachstumsserien von Humeri und Femora sowie umfassende Überlieferungen des Wachstums von Individuen anhand einzelner Knochen machen es wahrscheinlich, daß alle vier Sauropoden-Taxa der Tendaguru-Schichten durch ein auch nach der Geschlechtsreife anhaltendes Wachstum gekennzeichnet waren. Allerdings ging das Wachstum nicht bis zum Tode des Tieres weiter, sondern kam bei einer etwas variablen Maximalgröße zum Stillstand. Fibrolamellärer Knochen ist der vorherrschende Knochentyp in den Proben, was anzeigt, daß die Tendaguru-Sauropoden mit für Säugetieren typische Raten wuchsen. Die Tendaguru-Sauropoden kombinerten also ein für Reptilien typisches Muster des Wachstums, nämlich nach der Geschlechtsreife anhaltendes Wachstum, mit für Säuger typischen Raten des Wachstums. Die verschiedenen Sauropoden-Taxa zeigen erstaunliche Unterschiede in den Details ihrer Knochenhistologie, die Unterschiede in der Lebensgeschichte belegen. Bei Barosaurus scheint außerdem ein Geschlechtsdimorphismus in der Histologie der Langknochen vorzukommen. doi:1002/mmng.1999.4860020107

Download Full-text

Bone histology yields insights into the biology of the extinct elephant birds (Aepyornithidae) from Madagascar

Biological Journal of the Linnean Society ◽

10.1093/biolinnean/blaa013 ◽

2020 ◽

Vol 130 (2) ◽

pp. 268-295 ◽

Cited By ~ 2

Author(s):

Anusuya Chinsamy ◽

Delphine Angst ◽

Aurore Canoville ◽

Ursula B Göhlich

Keyword(s):

Life History ◽

Comparative Analysis ◽

Histological Study ◽

Early Ontogeny ◽

Bone Histology ◽

New Information ◽

History Of ◽

Biomechanical Constraints

Abstract Given that the biology of the recently extinct aepyornithids is poorly understood, we undertook a histological study of 29 skeletal elements of adult and juvenile specimens of Aepyornithidae, i.e. Aepyornis maximus, Aepyornis hildebrandti and Vorombe titan, in addition to a group of taxonomically unidentifiable juvenile Aepyornithiformes. Comparative analysis of the histology of the different skeletal elements showed that although the femur retained a good record of growth during early ontogeny, the tibiotarsus provided the best record of growth. Our data showed that, like other insular birds and their extant relative, the kiwi, Aepyornithidae experienced protracted growth. We also found that intracortical remodelling began early in ontogeny and continued throughout their lives, becoming more extensive throughout the compacta with age, albeit more restricted to the perimedullary region in the femora. We also deduced that the different skeletal elements experienced variable amounts of intracortical remodelling, which was most likely to be related to biomechanical constraints, size of the element and ontogenetic age. Additionally, we documented the occurrence of an unusual endosteal tissue within the large perimedullary erosional spaces of a femur of A. maximus. Overall, our study provided a lot of new information about the life history of these giant, recently extinct ratites.

Download Full-text