The golden mole is an underground tree shrew!

Updated October 11, 2016 with a new lateral view of the Chrysochloris skull. 

One more nail in the ‘Afrotheria’ coffin here.
The Cape golden mole (Chrysochloris asiatica, Linneaus 1758; 8-20cm in length) nests with the elephant shrew (Macroscelides) and together they nest with the tree shrew (Tupaia) in the large reptile tree, which scores morphology, not molecules. Prior studies nested golden moles with elephant shrews, tenrecs, aardvarks, hyraxes, elephants and sea cows in the purported clade ‘Afrotheria.’ The large reptile tree does not confirm such a clade.

Figure 1. The Golden Mole (Chrysocloris asiaticus) nests with the tree shrew and elephant shrew in the large reptile tree, not the common mole. Image copyright Digimorph.org and used with permission.

Figure 1. The Golden Mole (Chrysocloris asiaticus) nests with the tree shrew and elephant shrew in the large reptile tree, not the common mole. Image copyright Digimorph.org and used with permission.

Convergent with
Talpa, a true or common mole, and marsupial moles, the golden mole has taken to a life underground, with reduced ears and eyes, large fore claws and enormous shoulder muscles. Note the displacement of the scapulae to the top of the neck. And the pisiform evolves to become a second ulna! (Fig. 2).

Figure 2. Golden mole forelimb. The elongate pisiform (amber) essentially creates a second ulna. Only digits 1-4 are present.

Figure 2. Golden mole forelimb. The elongate pisiform (amber) essentially creates a second ulna. Only digits 1-4 are present. Image copyright Digimorph.org and used with permission.

Rather than broad claws
the golden mole third ungual is large and sharp. The other digits are reduced and digit 5 is absent. The lateral temporal fenestra and the jaw adductors therein, have been squeezed out as the squamosal laminates to the cranium (Fig. 3). And if you look close enough, there is a postorbital bar. But it too, is laminated to the cranium. The posterior jugal is tall and robust.

Figure 3. The lateral view of the golden mole (Chrysochloris) skull shows the tiny orbit and the complete  circumorbital bones, the jugal and frontal.   Image copyright Digimorph.org and used with permission.

Figure 3. The lateral view of the golden mole (Chrysochloris) skull shows the tiny orbit and the complete circumorbital bones, the jugal and frontal.
Image copyright Digimorph.org and used with permission.

 Like the tenrecs,
golden moles possess a cloaca (combined anus and genitals), and males lack a scrotum, but they are not as closely related to tenrecs. Like the Marcoscelides and Tupaia the tibia is longer than the femur in Chrysochloris, which is odd for a tetrapod that does not sprint.

Figure 2. Macroscelides proboscideus, the elephant shrew or sengis is NOT more closely related to elephants with the purported 'Afrotheria.' but instead is related to Tupaia, the tree shrew.

Figure 2. Macroscelides proboscideus, the elephant shrew or sengis is NOT more closely related to elephants with the purported ‘Afrotheria.’ but instead is related to Tupaia, the tree shrew.

Analysis indicates that certain tree shrews
in the Cretaceous descended to the ground. Elephant shrews became sprinters to defend themselves from dinosaur predators. Golden moles burrowed.

References
Linnaeus C 1758. Systema naturæ per regna tria naturæ, secundum classes, ordines, genera, species, cum characteribus, differentiis, synonymis, locis. Tomus I. Editio decima, reformata.

wiki/Golden_mole
wiki/Cape_golden_mole

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