To view this video please enable JavaScript, and consider upgrading to a web browser that supports HTML5 video Movie 2 Echocardiography of an anaesthetized Savannah Monitor in the transverse plane showing the ‘left’ ventricle as dense and circular with the ‘right’ ventricle nestled around it. Identification of the building blocks of ventricular septation in monitor lizards (Varanidae) Jermo Hanemaaijer, Martina Gregorovicova, Jan M. Nielsen, Antoon F. M Moorman, Tobias Wang, R. Nils Planken, Vincent M. Christoffels, David Sedmera, and Bjarke Jensen Development 2019. 146:None-None; doi: 10.1242/dev.177121 Download Original Video