“…This vein was similar to vessel named as the right marginal ventricular vein in mammalian [5,12,20,21,23] . This strong vein has been also reported in mice [15] and marsupial [18] In many mammals [5,12,[14][15][16][17][19][20][21]23] , main cardiac veins which are the great cardiac vein, middle cardiac vein, right cardiac veins and their secondary branches are well-defined in terms of the course they follow and the place they drain and that are present in a regular and specialised way, though they may display some variations. Unlike the mammals, as reported in the resources on birds [1,3,4,22] as well as in our samples, the size, number, distribution and origins of these secondary branches were observed to differ from sample to sample.…”