Anniealexandria is an extinct genus of amphisbaenian lizard known by the type species Anniealexandria gansi from the earliest Eocene of Wyoming. Anniealexandria is the only known member of the family Bipedidae in the fossil record, which otherwise only includes the extant genus Bipes from Mexico. It was named in 2009 in honor of Annie Montague Alexander, founder of the University of California Museum of Paleontology. Remains of Anniealexandria are known only from a single fossil locality in the Bighorn Basin called Castle Gardens, but within the locality its fossils are common in the Willwood Formation, usually consisting of isolated jaw bones and vertebrae. Anniealexandria seems to have been a common component of a paleofauna that included fifteen other lizard species and existed in western North America during a period of global warming in the latest Paleocene and earliest Eocene.

Below is a cladogram from Longrich et al. (2015) showing the phylogenetic relationships of Anniealexandria:

AmphisbaeniaRhineuridae †Chthonophidae Chthonophis subterraneus †Oligodontosaurus spp. Amphisbaeniformes Blanidae †Anniealexandria gansi Bipes spp. Cadea blanoides †Todrasaurus gheerbrandti Afrobaenia Trogonophis wiegmanni Diplometopon zarudnyi Agamodon anguliceps Amphisbaenidae
Rhineuridae
†Chthonophidae Chthonophis subterraneus †Oligodontosaurus spp. Amphisbaeniformes Blanidae †Anniealexandria gansi Bipes spp. Cadea blanoides †Todrasaurus gheerbrandti Afrobaenia Trogonophis wiegmanni Diplometopon zarudnyi Agamodon anguliceps Amphisbaenidae
†ChthonophidaeChthonophis subterraneus
†Oligodontosaurus spp. Amphisbaeniformes Blanidae †Anniealexandria gansi Bipes spp. Cadea blanoides †Todrasaurus gheerbrandti Afrobaenia Trogonophis wiegmanni Diplometopon zarudnyi Agamodon anguliceps Amphisbaenidae
†Oligodontosaurus spp.
AmphisbaeniformesBlanidae †Anniealexandria gansi Bipes spp. Cadea blanoides †Todrasaurus gheerbrandti Afrobaenia Trogonophis wiegmanni Diplometopon zarudnyi Agamodon anguliceps Amphisbaenidae
Blanidae †Anniealexandria gansi Bipes spp.
Blanidae
†Anniealexandria gansi Bipes spp.
†Anniealexandria gansi
Bipes spp.
Cadea blanoides †Todrasaurus gheerbrandti Afrobaenia Trogonophis wiegmanni Diplometopon zarudnyi Agamodon anguliceps Amphisbaenidae
Cadea blanoides
†Todrasaurus gheerbrandti Afrobaenia Trogonophis wiegmanni Diplometopon zarudnyi Agamodon anguliceps Amphisbaenidae
†Todrasaurus gheerbrandti
AfrobaeniaTrogonophis wiegmanni Diplometopon zarudnyi Agamodon anguliceps Amphisbaenidae
Trogonophis wiegmanni Diplometopon zarudnyi Agamodon anguliceps
Trogonophis wiegmanni
Diplometopon zarudnyi Agamodon anguliceps
Diplometopon zarudnyi
Agamodon anguliceps
Amphisbaenidae