FIGURE 1. Enchodontid species from the El Chango quarry, Chiapas, Mexico; A, IHNFG-2987, holotype of Unicachichthys multidentata; B, IHNFG-5816, holotype and single specimen of Veridagon avendanoi. Scale bar equals 1 cm.
FIGURE 2. Geological map and geographical localization of the El Chango quarry, Chiapas, Mexico.
FIGURE 3. A) Lateral view of Vegrandichthys coitecus gen. et sp. nov., IHNFG 5927 holotype transferred in plastic resin from Early Cenomanian deposits of the El Chango quarry, Chiapas, Mexico. B) Artistic reconstruction of Vegrandichthys coitecus gen. et sp. nov.
FIGURE 4. Vegrandichthys coitecus gen. et sp. nov. A) A close-up of the lateral view of the head; B) Drawing of the head and pectoral girdle in lateral view. Abbreviations: aa, anguloarticular; cl, cleithrum; den, dentary; df, dilatator fossa; dpl, dermopalatine, dpl.t, dermopaltine teeth; ect, ectopterygoid; en, endopterygoid; epo, epiotic; fr, frontals; hy, hyomandibula; io, infraorbital; iosc, infraorbital sensory canal; la, lacrimal; le, lateral ethmoid; mpt, metapterygoid; msc, mandibular sensory canal; mx, maxilla; op, opercle; pa, parietals; pmf, premaxillar fenestra; pmx, premaxilla; pop, preopercle; ps, parasphenoid; pte, pterotic; ptt, posttemporal; q, quadrate; rar, retroarticular; sc, sclerotic; scl, supracleithrum; soc, supraoccipital; sop, subopercle; sp, sphenotic.
FIGURE 5. Close-up of different anatomical structures in the holotype of Vegrandichthys coitecus gen. et sp. nov. A) Pectoral girdle and fin, B) Pelvic girdle and fin, C) Dorsal fin and D) Anal fin. All anterior structures are laterally exposed. Abbreviations: cl, cleithrum; co, coracoid; dpt.a, anal fin distal pterygiophores; dra, dorsal fin rays; lw, lateral wing; pb, pelvic bone; pfr, pectoral fin rays; pp, posterior process; ppt.a, anal fin proximal pterygiophores; ppt, proximal pterygiophores; pr, pelvic rays; ra.a, anal fin rays; scl, supracleithrum; v, vertebra.
FIGURE 6. Scutes, scales and associated bones of Vegrandichthys coitecus gen. et sp. nov. A) Dorsal scutes series, B) close-up of the dorsal scutes region, C) close-up of the lateral line of scales, and D) drawing of the probable position and overlapping of the lateral line of scales. Abbreviations. llc, lateral lines canal; l.sc, lateral line scales; v, vertebrae. Ordinal numbers denote the number of dorsal scute. Black arrows point out each of the dorsal scutes. Red arrows point out the supraneurals.
FIGURE 7. Phylogenetic relationships of Enchodontidae including Vegrandichthys coitecus gen. et sp. nov. obtained following the protocol described of the Standard of Maximum Parsimony (TL= 316, CI = 0.456, RI= 0.693). Numbers by nodes indicate the supports values of Bremer/Bootstrap. Black squares indicate the presence of synapomorphic characters in Enchodontidae. Node a, Enchodontidae: presence of anteroventral prongs (36:1); absence of supraorbital bone (43:1); pelvic fin at or posterior to the dorsal fin in position (52:1); opercular and subopercular dermal pattern as tubercles (55:2). Node b: Laminar posterior limb in the ventral portion of the preopercle (50:0). Node c: Ectopterygoid teeth between six to eight teeth with the second tooth longest (12:2). Node d, Subfamily Eurypholinae: Ventral portion of cleithrum widens anteriorly and posteriorly (60:2). Node e: Laterally exposed articulation mandible-quadrate (34:1); Opercular horizontal strengthening ridge continues past posterior edge to form a spine (52:2). Node f: Mandibular dermal pattern as ridges with tubercles along each ridge (41:2); Preopercular dermal pattern as ridges with tubercles (54:2). Node q: Sigmoidal lateral view of dermopalatine teeth (16:2). Numbers by nodes show the Bremer/Bootstrap values. The subfamily Enchodontinae is only supported by homoplastic characters, therefore, we omitted them in the node description. Full description and character mapping are in Appendix II.
FIGURE 8. Results of the inclusion of Vegrandichthys coitecus gen. et sp. nov. in the phylogeny of Enchodontidae using multiple phylogenetic approaches. A) The one retained tree of Enchodontidae with the Phylogenetic Morphometrics (PM) method using only landmark data, the Best Score reached = 0.04079. B) Dots in red correspond to the landmark configuration of the preopercle used to run the PMA. C) Implied Weighted Maximum Parsimony (IWMP) tree (the same tree topology with K=10 and K=100) based exclusively on discrete morphological data. D) Maximum a Posteriori (MAP) phylogeny obtained with Bayesian Inference. E) Tree obtained with the combined matrix of morphological discrete data and the landmark configuration of the preopercle, using Standard Maximum Parsimony; Best score = 316.04924. In green background is the subfamily Eurypholinae, except in A that includes Unicachichthys. Background in red is the clade formed by Parenchodus + Enchodus species. In all the phylogenetic analyses Vegrandichthys coitecus gen. et sp. nov. new is recovered as a member of the subfamily Eurypholinae along with Eurypholis and Saurorhamphus. Numbers by nodes indicate Bremmer / bootstrap (when present) values except in D, where numbers indicate the posterior probability. Full phylogenetic hypotheses and their description can be accessed in Appendix II.
FIGURE 9. Assessment of the stratigraphic congruence in Enchodontidae. A) Phylogeny including Enchodus zimapanensis and B) phylogeny excluding it. Both phylogenies time-calibrated and plotted against the ICS 2019 data. Red branch points out the phylogenetic position of Vegrandichthys coitecus gen. et sp. nov. Below each tree, there are the histograms of the SCI for the input and randomly generated topologies.
