Figure 2 in On cosmine: its origins, biology and implications for sarcopterygian interrelationships

Figure 2. – Phylogenetic implications and evolutionary scenario of cosmine development in osteichthyans. Numbers 1-4 detailed in the text (Development of cosmine). A: phylogenetic interrelationships of selected osteichthyans (after Lu et al., 2017) and interpretative reconstructions of taxa; B: histological cross sections; C: illustrations of the histological structures from the cross sections; D: virtual and ideal- ized reconstructions of the pore-canal system of the cosmine. Sources of cross sections and drawings: Andreolepis: Zhu et al., 2010, Qu et al., 2013b, 2016; Psarolepis: Qu et al., 2013a, 2016; Meemannia: Zhu et al., 2010; Styloichthys: Zhu et al., 2006; Porolepis: Gross, 1956; Mondéjar-Fernández and Clément, 2012; Dipterus: Gross, 1956; Osteolepis: Gross, 1956, Schultze, 2015; Megalichthys: Gross, 1956; Thomson, 1975. Scale bar = 100 µm. Abbreviations: ba, basal extension; cc, cross canal; d, dentine; dt, dentinal tubules; e, enamel; lmc, lower mesh canal; mc, mesh canal; od, odontode; pc, pore cavity; po, pore opening; puc, pulp cavity.