RHABDODONTOIDEA, 2022

Poole, Karen E., 2016, Phylogeny of iguanodontian dinosaurs and the evolution of quadrupedality, Palaeontologia Electronica (a 30) 25 (3), pp. 1-65 : 17-18

RHABDODONTOIDEA new clade name

Phylogenetic definition. A stem-based taxon including all taxa more closely related to Zalmoxes robustus and Rhabdodon priscus than to Dryosaurus altus .

Unambiguous synapomorphies. The smaller clade found in the parsimony analysis is characterized by four unambiguous synapormorphies: a sub-rectangular orbit (34.1), sinuous ventral edge of the jugal (56.1), caudodorsally extending postacetabular process of the ilium (265.1), and a femur that is straight in lateral view (290.0).

The larger Bayesian clade has two unambiguous synapomorphies: maxilla with a broad triangular dorsal process (21.1), and a straight maxillary toothrow in ventral view (26.2).

Topology. The parsimony analysis ( Figures 6 , 7 ) recovers a clade containing rhabdodontids, Tenontosaurus , and Muttaburrasaurus ; this is supported by a jackknife value of 23, and Bremer support of 4.

The Bayesian analysis ( Figures 6 , 8 ) also finds Tenontosaurus and Muttaburrasaurus as the sister taxa to Rhabdodontidae , but this is included within a larger clade with many Gondwanan taxa ( Kangnasaurus , Anabisetia , Trinisaura , and Talenkauen ). The basal node of the clade is poorly supported (PP=0.24), though the node supporting Rhabdodontidae , Muttaburrasaurus , and Tenontosaurus has stronger support (PP=0.85).

Figures

FIGURE 6. Parsimony (left) and Bayesian (right) trees plotted together. Strict consensus of 84 MPTs after pruning Oryctodromeus, Atlascopscosaurus, Planicoxa, Cumnoria, Cedrorestes, and NHMUK R28860. Jackknife values above 20 (with 10% chance of character removal) are shown above and to the left of their respective nodes. Bremer supports above one are shown below and to the left of their respective nodes, and bolded. CI=0.272, RI=0.634. Maximum clade credibility tree produced by Bayesian analysis showing posterior probabilities below and to the right of their respective node.

FIGURE 7. Time scaled parsimony tree, showing assigned age ranges and broad-scale geographic data. Jackknife values above 20 (with 10% chance of character removal) are shown above and to the left of their respective nodes. Bremer supports above one are shown below and to the left of their respective nodes, and bolded.

FIGURE 8. Maximum Clade Credibility tree produced by Bayesian analysis. Posterior probabilities are shown to the left of their nodes. The geologic timescale is shown across the top. Tips represent the average age found for each OTU across all sampled trees.