NOVEL DISCOVERY OF OSSA CORDIS IN THE RETICULATED GIRAFFE (Giraffa reticulata)
DOI:
https://doi.org/10.26873/SVR-2342-2026Keywords:
calcium, collagen, microscopy, trabeculation, X-ray computed microto-mographyAbstract
Ossa cordis and cartilago cordis are heterotopic bone and cartilage, respectively, in the cardiac skeleton of the heart. Relatively few species have cartilage cordis, an even smaller number have ossa cordis, and very few observations of cartilage surrounding ossa cordis have been published. In species presenting with ossa cordis, the prevalence, anatomical location, histological structure, architecture, number of ossa cordis per heart, existence of cartilage circumventing the bone, and links to cardiovascular disease vary between species, and between individuals of the same species. The current, novel, research utilized X-ray computed microtomography (μCT) in the cardiac skeleton of the reticulated giraffe (Giraffa reticulata, formally Giraffa camelopardalis reticulata). A giraffe ossa cordis has also never been observed using histological and microscopic methods. Therefore, haematoxylin and eosin (H&E), special stains Von Kossa (indicating calcium deposits), Alcian blue pH 0.2 and 2.5 (indicating acidic polysaccharides, such as glycosaminoglycan present in cartilage) and immunohistochemistry alongside light microscopy, and Picrosirius red (indicating collagen) with polarized light microscopy accompanied the μCT study. This research established the size, shape and microstructure, including bone thickness throughout the giraffe ossa cordis using dissection and μCT. The types of bone and cartilage were identified using histological methods, and detailed microstructure aspects including collagen quantity and types, vasculature and disease status. This work also explored the theories relating to endochondral and intramembranous ossification. Importantly, this case study described giraffe ossa cordis shape, size, microstructures and histological features for the first time.
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Copyright (c) 2026 Craig J. Sturrock, Adam Best, Aziza Alibhai, Jorja Jackson-Oxley, Jennie J. Jeyapalan, Brian Atkinson, William Perez, Catrin Sian Rutland*
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