FIGURE 1. Map of the San Ignacio region within the Baja California Peninsula, Mexico, source of the fossil specimens of Vaquerosella referred in this manuscript. A, general view of the lower part of the Baja California Peninsula showing the San Ignacio region. B, geological map of the San Ignacio region showing the sites IGM-loc 248 and IGM-loc 265 (modified from Romero-Rojas et al., 1997).
FIGURE 3. Nominal species in the genus Vaquerosella Durham, 1955. A, V. andersoni (Twitchell, in Clark and Twitchell, 1915) Holotype USNM PAL 165719A. B, V. coreyi Durham, 1955 Holotype UCMP 31712. C, V. durhami Adegoke, 1969 Holotype UCMP 36566. D, V. merriami (Anderson, 1905) Syntype CAS 66758-01. E, V. norrisi (Pack, 1909) Holotype UCMP 11028. F, V. vaquerosensis (Kew, 1920) paratype UCMP 11403. Images taken from their online collection databases (USNM PAL https://collections.nmnh.si.edu/search/paleo/; UCMP https://ucmpdb.berkeley.edu/) Scale bar equals 1cm.
FIGURE 6. Multi-focal macroscope images of Vaquerosella perrillatae sp. nov. A, Apical system monobasal in IGM 11471. B, Conjugated pairs of pores in IGM 11472. C, Frontal ambulacrum in in IGM 11471. D, Ambulacrum IV in IGM 11473. E, Peristome with basicoronal plates in IGM 11471. F, internal support developed as concentric bars.
FIGURE 8. Phylogenetic hypothesis of the genus Vaquerosella obtained in this work. Nodes and terminal branches show the supporting characters and the respective changes on the states of characters [character (original state→final state)], Bremmer and Bootstrap supports values are shown near to each node [Bremmer/Bootstrap].
FIGURE 9. Distribution of the specimens included in the phylogenetic analysis. Gray diamond: Astrodapsis spatiosus, Santa Margarita Formation; Black diamond: Astrodapsis bajasurensis, Isidro Formation; Black star: Vaquerosella perrillatae sp. nov., San Ignacio Formation; Black circle: Vaquerosella reports along Shibiwaka, Temblor and Vaqueros Formation.