TY - BOOK
T1 - Revision of the fossil batomorphs from the Cretaceous of Lebanon, and their impact on our understanding of the early step of the evolution of the clade
AU - Kachacha, Georges
PY - 2016
Y1 - 2016
N2 - Herein after introducing the subject, a historical state of the art and an overview on the known geological setting of the Upper Cretaceous Lebanese outcrops (Sahel Aalma, Nammoura, Haqel and Hjoula) are given in addition to few preliminarily geochemical analyses. Teeth morphology and histology's detailed studies were performed enabling to give new insights on the complexity and diversity of their enameloid microstructure. A bundled crystallite enameloid is widespread among Rhinobatoidei teeth tested so far, whereas, the parallel bundled enameloid component is considered an apomorphy for this group. However, the complexity and diversity of the enameloid layers presents an ambiguous phylogenetic signal since it varies greatly between and within species and appears more related to tooth morphology than to tooth size. A redescription of the 12 batomorph taxa known from the Lebanese outcrops is provided (based on type material and additional well-preserved and complete material). Two new species are described and Gen nov. 1 grandis is reestablished. A set of 65 morphological characters (among which 11 are new) has been established. These characters are used in a cladistic phylogenetic study based on 36 taxa. Eleven most parsimonious trees were obtained (CI = 0.394 and RI = 0.652). The consensus results do not recover the monophyly of Rhinobatidae. Three shark-like Lebanese guitarfish, assigned to Rhynchobatidae, are nested together with Rhynchobatus at the bottom of the tree and considered as sister group to the remaining batomorphs. The remaining guitarfish from Lebanon present a crown paraphyletic assemblage sister to Rajidae, which, together, are included in the order Rajiformes. Eight Lebanese guitarfishes are distributed into four different clades which allowed me to reconsider the generic assignment of these taxa. Thus four new genera were erected to accommodate these clades. Cyclobatidae and Myliobatiformes are recovered into a clade including Tethybatis and sister to Torpediniformes. The monophyly of Rajidae is recovered and Raja davisi, together with a new species are sister to the extant Raja. Finally, Platyrhinidae is recognized as a monophyletic group of true guitarfish, successively rooted by Britobatos primarmatus and Rhombopterygia rajoides. Keywords: batomorphs; Upper Cretaceous; enameloid microstructure; cladistics
AB - Herein after introducing the subject, a historical state of the art and an overview on the known geological setting of the Upper Cretaceous Lebanese outcrops (Sahel Aalma, Nammoura, Haqel and Hjoula) are given in addition to few preliminarily geochemical analyses. Teeth morphology and histology's detailed studies were performed enabling to give new insights on the complexity and diversity of their enameloid microstructure. A bundled crystallite enameloid is widespread among Rhinobatoidei teeth tested so far, whereas, the parallel bundled enameloid component is considered an apomorphy for this group. However, the complexity and diversity of the enameloid layers presents an ambiguous phylogenetic signal since it varies greatly between and within species and appears more related to tooth morphology than to tooth size. A redescription of the 12 batomorph taxa known from the Lebanese outcrops is provided (based on type material and additional well-preserved and complete material). Two new species are described and Gen nov. 1 grandis is reestablished. A set of 65 morphological characters (among which 11 are new) has been established. These characters are used in a cladistic phylogenetic study based on 36 taxa. Eleven most parsimonious trees were obtained (CI = 0.394 and RI = 0.652). The consensus results do not recover the monophyly of Rhinobatidae. Three shark-like Lebanese guitarfish, assigned to Rhynchobatidae, are nested together with Rhynchobatus at the bottom of the tree and considered as sister group to the remaining batomorphs. The remaining guitarfish from Lebanon present a crown paraphyletic assemblage sister to Rajidae, which, together, are included in the order Rajiformes. Eight Lebanese guitarfishes are distributed into four different clades which allowed me to reconsider the generic assignment of these taxa. Thus four new genera were erected to accommodate these clades. Cyclobatidae and Myliobatiformes are recovered into a clade including Tethybatis and sister to Torpediniformes. The monophyly of Rajidae is recovered and Raja davisi, together with a new species are sister to the extant Raja. Finally, Platyrhinidae is recognized as a monophyletic group of true guitarfish, successively rooted by Britobatos primarmatus and Rhombopterygia rajoides. Keywords: batomorphs; Upper Cretaceous; enameloid microstructure; cladistics
UR - https://rex.kb.dk/primo-explore/fulldisplay?docid=KGL01010309085&context=L&vid=NUI&search_scope=KGL&tab=default_tab&lang=da_DK
M3 - Ph.D. thesis
BT - Revision of the fossil batomorphs from the Cretaceous of Lebanon, and their impact on our understanding of the early step of the evolution of the clade
PB - Natural History Museum of Denmark, Faculty of Science, University of Copenhagen
ER -