Figure 1 in On cosmine: its origins, biology and implications for sarcopterygian interrelationships

Figure 1. – Interrelationships and geological time range of selected osteichthyans (histologically surveyed taxa or with important phylogenetic implications). Phylogenetic hypothesis after Ahlberg and Johanson, 1998; Johanson and Ahlberg, 2001; Zhu et al., 2001, 2006, 2009, 2017; Friedman, 2007; Snitting, 2008; Lu and Zhu, 2010; Coates and Friedman, 2010; Lu et al., 2012, 2017; Choo et al., 2017, among others. The dates of origin of clades are hypothetical. Abbreviations: A: Actinopterygii, D: Dipnomorpha, R: Rhipidistia, S: Sarcopterygii, T: Tetrapodomorpha. Legends: light grey with large dots: primitive type of cosmine as described in early osteichthyans (presence of large pores associated with a variably developed pore-canal system in the dentine and superimposed odontodes); light grey with fine dots: eucosmine (presence of minute pores associated with a pore-canal system in the dentine overlaid by a single layer of enamel); light grey: odontogenic derivatives of cosmine: ganoine (in actinopterygians), tubercles solely made of dentine or a combination of enamel and dentine (early osteichthyans and sarcopterygians); white: bony ornamentation (absence of odontogenic tissues in the dermoskeleton).