Figure 2
From: A putatively extinct higher taxon of Spirotrichea (Ciliophora) from the Lower Cretaceous of Brazil
Light microscopy photographs (a,c,h) and volumetric reconstructions (b,d,e–g,i) of Palaeohypothrix bahiensis gen. et sp. nov. holotype. (a) Z-stack of photographs to compose the entire ventral surface. Ventral side. (b) Right side to show presumed contractile vacuole. (c,d) Detail of nuclear apparatus; bottom right inset in c. to show slightly different focal plane. (c) Ventral view. (d) Right lateral view assembled from two longitudinal sections to show both macronuclear nodules, circumscribed by dotted line. (e) Ventrolateral view to show the adoral zone of membranelles; figure inset shows detail of one lapel membranelle. Asterisk marks oral cavity; black and white arrowheads point to distal and proximal ends of lapel adoral zone, respectively (same in f). (f) A ventral focal plane under simulated oblique illumination. (g) Transversal section showing oral cavity (asterisk). (h,i) Detail of paroral. (h) Bright field photograph. (i) Simulated oblique illumination. Arrowhead shows insertion pits of frontal brushes; asterisks mark ciliary brushes which compose the paroral. Legends: AZM adoral zone of membranelles, Ch vestige of chromatin condensation, CV contractile vacuole, F frontal ciliary structures, FV fronto-ventral ciliary structures, LM left marginal ciliature, Ma macronuclear nodule, Mi micronucleus, P paroral membrane, RM right marginal ciliature. Scale bar = 20 µm.
