In contrast, until now only few morphological synapomorphies, notably placental morphology [ 30], an increase in number of thoracolumbar vertebrae [ 31], and testicondy [ 32], appear to support this grouping.
Smerinthini, even excluding Langia and Sphingulini, are a morphologically heterogeneous group for which morphological synapomorphies are lacking.
The resolution of notothenioids within "trachinoids" in a previous phylogenetic analysis was potentially the result of morphological synapomorphies shared with Percophis [ 30], but relationships were likely obfuscated by scoring morphological character states for "percophids" as a single taxon that comprised the polyphyletic assemblage comprising Bembrops, Percophis and Hemerocoetes [ 31, 64].
There are groups of species e.g. from Microlepidoptera, Pyralidae, that are far more difficult to assign morphologically to taxa and lack of morphological synapomorphies may reflect the instability of the current classification.
With Afrosoricida placed as the sister group of all other afrotherians, there was only one unambiguously optimized morphological synapomorphy of Afrotheria in the OSA (placement of the root of the zygomatic lateral to M3), none in the UA, but 24 (UA) to 30 (OSA) ambiguous morphological synapomorphies of that clade.
Phylogenetic relationships within Conchifera are also far from settled due to the highly derived morphologies within each class-level grade, which hinder the discovery of morphological synapomorphies across lineages [ 17].
Considerable ambiguity is introduced by missing data and different methods for optimizing character states onto slightly different afrotherian phylogenies, but it remains distinctly possible that there are a number of morphological synapomorphies of crown Afrotheria, and that the ancestral crown afrotherian more closely resembled a "proto-ungulate" than an "insectivore".
These morphological synapomorphies with extant serrasalmid species place M. paranensis as sister taxa to the carnivorous "piranha-clade" and a more distant intermediate relative to the herbivorous "pacu-clade" (SI Fig. 1). Figure 1: Skull anatomy of S. rhombeus (photo by SH) and fossil teeth of M. paranensis (inset, reprinted from Cione et al.).
The lack of strong morphological synapomorphies to distinguish it from related genera in the region necessitates molecular data in ascertaining generic placements (Xu et al. 2012ab).
This is surprising for a group whose monophyly and morphological synapomorphies appear quite clearly [35].
