 A comparison of the tarsometatarsi of two "B. burmeisteri" specimens, FM-P13259 and MLP-91 (lectotype), both coming from the same geographical region and geological formation, shows them as not to present any anatomical differences, apart from size, where in the first is around one third smaller than the second.The idea is that they are examples of intraspecific variation, possibly sexual dimorphism.There is the possibility that they represent two species.