What is Brachiosauridae?

All taxa more closely related to Brachiosaurus altithorax than to Saltasaurus loricatus.
It was first defined in 1998 by Wilson and Sereno as "all titanosauriforms more closely related to Brachiosaurus than to Saltasaurus", and later by Sereno in 2005 online as "the most inclusive clade containing Brachiosaurus brancai but not Saltasaurus loricatus, Euhelopus zdanskyi and Camarasaurus lentus".
However, the PhyloCode dictates that full species names (generic name + specific name) must be used as group specifiers, which rules out Wilson and Sereno's initial definition as it only uses generic names. Plus, the internal specifier of a group (in this case, Brachiosaurus) must be the type species of its genus, which rules out Sereno's later definition because Brachiosaurus brancai was recently renamed Giraffatitan, and it was never the Brachiosaurus type species anyway. Coming soon. In the meantime click here to search Dinochecker for brachiosaurids. Brachiosauridae is derived from the Greek "brachios" (arm), "sauros" (lizard) and "idae" (family), referring to their very long front legs (arms) and their relationship to Brachiosaurus; the original arm lizard.