“…In the ageing human heart, calcium deposits have been reported in the right and left fibrous trigones (Tohno et al, 2007 ; Trainini et al, 2021 ; Trainini et al, 2022 ). Whilst the presence of Ossa cordis occurs mainly in larger species, cartilage within the cardiac skeleton ( Cartilago cordis ), which does not appear to develop into bone, has been observed in many species including hamsters, snakes, chickens, quails, chinchillas, iguanas, terrapins, horses, dogs and rhinoceros (Duran et al, 2004 ; Erdogan, Lima, & Perez, 2014 ; Jurado et al, 2006 ; Lopez et al, 2003 ; Lopez, Duran, & Sans‐Coma, 2000 ; Lopez, Fernandez, Duran, & Sans‐Coma, 2001 ; Schmack, 1974 ; Warchulska et al, 2016 ; Young, 1994 ). This review summarizes the literature available regarding the Ossa cordis in different mammalian species.…”