(and possible also the third) centrale. Some lepospondyls, such as the reptile-like microsaur Tuditanus, also may have evolved these modifications. The ankle of Westlothiana, as well as that of most other "reptiliomorphs", is intermediate between these two conditions. Smithson (1989) reported that "Lizzie" had nine ankle bones, including an astragalus and calcaneum, and that the third and fourth centrales were already fused or lost. Yet he also noted that centrales one and two (which formed the navicular bone) were unfused. Smithson et al. (1993) later claimed that there were ten bones, arguing that the components of the astragalus were not completely fused, with the intermedium and tibiale still separate. Piñeiro, Demarco, & Meneghel (2016) could not determine which of these two interpretations were superior, but did note that the largest bone more closely resembled a fused astragalus rather than an unfused intermedium. The foot was most likely five-toed, with a phalangeal formula (the number of phalanges per toe from the innermost to outermost toe) of 2-3-4-5-4. This formula is identical to that of early amniotes, but conversely the foot of Westlothiana is shorter and more robust than the long-toed feet of amniotes. Additionally, the phalanges decrease in relative size towards the tip of the foot in this genus, while the opposite is true of amniotes. Phylogeny The phylogenetic placement of Westlothiana has varied from basal amniote (i.e. a primitive reptile) to a basal Lepospondyl, in analyses with the lepospondyls branching off from within Reptiliomorpha. The actual phylogenetic position of Westlothiana is uncertain, reflecting both the fragmentary nature of the find and the uncertainty of "labyrinthodont" phylogeny in general. The modern consensus on the classification of Westlothiana, as supported by analyses such as Clack (2002), Ruta et al. (2003), and Ruta & Coates (2007) considers the genus to be the earliest diverging (most "basal" or "primitive") member of Lepospondyli. Westlothiana'''s placement in Lepospondyli supports the hypothesis that lepospondyls are not very distant from amniotes. However, modern lissamphibians are sometimes considered to be descended from lepospondyls. Therefore, Westlothiana'' may actually be closer to modern amphibians than to amniotes, although still close to both. See also Casineria Solenodonsaurus References External links Westlothiana lizzae "fact file" from the National Museum of Scotland, with corresponding images of the type specimen and life restorations. 2D, Stereoscopic, and 3D imagery of the type specimen of Westlothiania lizzae Enigmatic vertebrate taxa Reptiliomorphs Carboniferous tetrapods Basal tetrapods of Europe