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The mole-like golden moles.

The hedgehog-like tenrecs.

The shrew-like sengis.

The rodent-like hyraxes.

The anteater-like aardvarks.

The whale-seal-hybrid-like sirens.

The tapir-like proboscideans.

All these mammals, diverse in appearance, actually belong to one superorder, called Afrotheria. Which raises the question — what are the anatomical characteristics common to all afrotheres?

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  • $\begingroup$ your question is confusing as it is worded/structured. It's fine that you rolled-back my attempted edits, but I suggest that you provide some context at the beginning of your question to help reduce the confusing structure of your question. $\endgroup$ – theforestecologist Feb 13 '17 at 18:56
  • $\begingroup$ I did. It can't have been any more straightforward. $\endgroup$ – JohnWDailey Feb 13 '17 at 19:02
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The word "Afrothere" comes from Latin Afer (referring to Africa) and Ancient Greek θηρίον ‎(thēríon, meaning “beast”). In other words, "Afrothere" etymologically refers to animals with origins in Africa.

So really, Afrotheria and it's members are referred to based on their origins and not their physical characteristics. In other words, they needn't share morphological characteristics, but rather they all evolved from the same common ancestor from Africa.

From the Afrotheria Wikipedia page:

Afrotheria is a clade of mammals, the living members of which belong to groups that are either currently living in Africa or [are] of African origin...

They share few anatomical features but many are partly or entirely African in their distribution

These animals are all chordates of the class Mammalia, and therefore do share the common "basal" characteristics shared among all members of these higher taxanomic levels -- for example, a notochord (and backbone), hair, three middle ear bones, mammary glands, etc.

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  • $\begingroup$ Emphasize on the "few anatomical features". A little clarification is required. $\endgroup$ – JohnWDailey Feb 13 '17 at 18:33
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    $\begingroup$ @JohnWDailey The few characteristics they share are those shared with common ancestors. I've listed some of these in my final paragraph. $\endgroup$ – theforestecologist Feb 27 '17 at 21:05
  • $\begingroup$ And what are those "few characteristics"? That last paragraph answers what makes a mammal a mammal, not what makes an afrothere an afrothere. And location is very circumstantial. $\endgroup$ – JohnWDailey Feb 27 '17 at 22:21
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    $\begingroup$ @JohnWDailey that's right. Because the only characteristics that afrotheres consistently share are those characteristics shared basally by all mammals. $\endgroup$ – theforestecologist Mar 31 '17 at 22:02
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    $\begingroup$ There grouping is based purely on genetics not morphology, although there are a few of those. vertibral count tandfonline.com/doi/abs/10.1017/S1477200006002258 and placental membranes onlinelibrary.wiley.com/doi/10.1002/jez.b.21079/… $\endgroup$ – John Mar 31 '17 at 23:56
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@theforestecologist is right, there are very few anatomical synapomorphies (shared derived traits) if any of Afrotheria, and the few there are almost all exhibit homoplasy. But if you want obscure putative anatomical synapomorphies that may not strictly hold:

" presence of a naviculocalcaneal facet scattered vomeronasal organ blood vessels, placement of the internal carotid lateral to the anterior pole of pars cochlearis four allantoic vessel chambers Presence of a small P3 protocone presence of well-developed buccal cingula rather than stylar shelves increase in lumbar vertebra number from 6 to 8 testicondy (intrabdominal testes)"

Are listed by Seiffert 2007 as possibilities-- but only under certain phylogenetic constructions.

Ref: Seiffert 2007 A new estimate of Afrotherian phylogeny based on simultaneous analysis of genomic, morphological, and fossil evidence. BBC Evolutionary Biology. https://bmcevolbiol.biomedcentral.com/articles/10.1186/1471-2148-7-224

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