The First Occurrence in the Fossil Record of an Aquatic Avian Twig-Nest with Phoenicopteriformes Eggs: Evolutionary Implications
Figure 6
Comparison of the Palaelodidae and Phoenicopteridae distal tibiotarsi.
(a) Phoenicopterus ruber (MZUSP 88485); (b) BAS new species; (c) Agnopterus sicki (MHNT 4257); (d) Phoenicopterus croizeti (MHNT 5085); (e) Palaelodus spp. (MHNT 5010). The most diagnostic characters found in BAS are a crest in the Retinaculum Extensorium Tibiotarsi (RET) divided by a deep and conspicuous sulcus from the articular facet for the intercotylar eminence of the tarsometatarsus (b), a deep intercondylar incision extending over the lateral condyle, a tuberosity for the RET medial attachment and a deep sulcus surrounded by crests cranial to the trochlea cartilaginis tibialis (not shown). RET: Retinaculum Extensorium Tibiotarsi. SRET: sulcus between the RET and the articular facet for the intercotylar eminence of the tarsometatarsus in the BAS specimen.