López-Torres and Fostowicz-Frelik seek to understand
the phylogenetic position of the Anagalidae, “an enigmatic and poorly studied group of primitive members of Euarchontoglires known from the Palaeogene of China.”
On the other hand
this clade is well understood in the large reptile tree (LRT, 1311 taxa, subset Fig. 3). The genus Anagale (Fig. 1) is basal to Andrewsarchus, tenrecs and odontocetes, taxa notably missing from traditional lists (see below). Taxon inclusion is the key to understanding this and all other tetrapod clades.
First of all, some traditional clade members:
- Traditional Euarchontoglires = rodents, lagomorphs (rabbits) treeshrews, colugos and primates.
- Traditional Anagalidae = elephant shrews, rodents and lagomorphs.
- Traditional Anagaloidea = also includes Zalambdalestes (a Solenodon (clade = Glires) sister in the LRT).
None of these groupings
are recovered in the LRT (which is genus to specimen-based).
Figure 1. Anagale nests at the base of the tenrec – odontocete clade, not with rabbits, in the LRT.
All prior clade memberships suffer from taxon exclusion.
Anagale (Figs, 1, 2) itself nests at the base of the tenrec – odontocete clade (Fig. 2) a hypothesis first recovered in the LRT.
Where Anagale and kin nest in the LRT:
- Anagalidae = Anagale (Fig. 2), some but not all elephant shrews, tenrecs, pakicetids, toothed whales and their kin. In other words, this is the tenrec-odontocete clade.
Figure 2. Odontoceti (toothed whale) origin and evolution. Here Anagale, Andrewsarchus, Sinonyx, Hemicentetes, Tenrec Indohyus and Leptictidium precede Pakicetus. Maiacetus and Orcinus are aquatic odontocetes.
López-Torres and Fostowicz-Frelik 2018 report:
“Anagalids were originally suggested to be closely related to modern treeshrews, lagomorphs, some primitive eutherian groups such as zalambdalestids and pseudictopids, and Macroscelidae (within the broader concept of ‘Anagalida’), but that idea was later rejected, especially with growing evidence of molecular relationships among major mammalian clades and the generally accepted monophyly of Glires. Our study presents a new, more comprehensive phylogenetic analysis based on 190 dental characters.”
Figure 5. Subset of the LRT focusing on the tenrec/odontocete clade with several whales added.
Dental characters only???
Yikes. The authors continue: “The resulting strict consensus tree (based on 76 equally-parsimonious trees) disagrees with the previous conception of anagalid monophyly. Instead, anagalids are heavily paraphyletic, appearing as several offshoots at the base of Glires, which suggests that anagalids could be considered stem Glires.”
The LRT is nearly fully resolved and anagalids are not stem Glires.
They are the sisters to Glires. Add these relevant taxa (Fig. 2) and let us know if your tree recovers the same tree topology.
These authors need to expand their taxon and character lists.
Contra tradition, Anagale and kin have little to do with rodents or rabbits. Add taxa. Let the taxa nest where they want to. Don’t limit the taxon list. Soon this clade will be well understood, no longer an enigma.
López-Torres S and Fostowicz-Frelik L 2018. The phylogenetic position of the Anagalidae within Euarchontoglires and its implication for the evolution of Glires and Euarchonta. SVP abstract.