Scale bar equals 2 mm. Photo from Kirk & Williams (2011).
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| Lingual view (side that touches the tongue) of Mescalerolemur horneri partial mandible. |
Do you know that fossil primates once roam North America? I didn’t know either so this discovery was a shock and a “d’oh” moment at the same time.Anywho … A fossil primate from the Eocene Epoch was discovered in Devil’s Graveyard badlands of West Texas by Anthropologists Christopher Kirk and Blythe Williams. Named Mescalerolemur horneri, this new fossil primate lived about 43 million years ago is a member of the extinct group, adapiforms, that are found all over the Northern Hemisphere. Mescalerolemur looked like a modern-day greater dwarf lemur and weighs about 370 grams.Interestingly enough, Mescalerolemur are more closely related to Eurasian and African adapiforms than those from North America. Darwinius masillae, famously known as Aunt Ida, was a Eurasian adapiform. Another interesting fact to point out is that Mescalerolemur had unfused mandibular symphysis, similar to those of Strepsirrhines (lemurs, lorises and galagos). The authors posit that this is definitive evidence that adapiforms are more similar to Strepsirrhines than Haplorrhines (humans are Haplorrhines). Kirk &Williams (2011) published their findings on Journal of Evolution: New adapiform primate of Old World affinities from the Devil’s Graveyard Formation of Texas (PDF). You can also read more about the discovery at EurekAlert: Anthropologist discovers new fossil primate species in West Texas.
SRC: Primatology.net
Various forms of fossil primates existed in North America...there are many species of early primates from North America. In fact, some entire families are known only from North America (‘unique' in brackets). The following families include the North American genera listed as examples; the dates apply to North American examples:
ReplyDeleteFamily Purgatoriidae (Early Palaeocene, unique) e.g. Purgatorius
Family Microsyopidae (Late Palaeocene-Middle Eocene) e.g. Niptomomys, Uintasorex, Navajovius, Arctodontomys, Microsyops, Megadelphus, Craseops.
Family Micromomyidae (Late Palaeocene-Early Eocene, unique) e.g. Micromomys, Myrmekomomys, Tinimomys, Chalicomomys.
Family Picromomyidae (Early-Middle Eocene, unique) e.g. Picromomys, Alveojunctus)
Family Plesiadapidae (Early Palaeocene-Early Eocene) e.g. Pandemonium, Saxonella, Pronothodectes, Chiromyoides, Nannodectes, Plesiadapis
Family Palaechthonidae (Early-Late Palaeocene, unique) e.g. Palaechthon, Premnoides, Anasazia, Palenochtha, Plesiolestes
Family Picrodontidae (Early-Late Palaeocene, unique) e.g. Draconodous, Picrodus, Zanycteris
Many people consider the Dermoptera to be a separate order, but McKenna and Bell (1997) in ‘Classification of Mammals Above the Species Level) includes this group in the Primates. There were several North American forms including Thylacaelurus and the following:
Family Paromomyidae (Early-Middle Eocene) e.g. Paromomys, Simpsonlemur, Elwynella, Ignacius, Pulverflumen, Dillerlemur, Phenacolemur
Family Plagiomenidae (Early Paleocene-Late Oligocene, unique) e.g. Elpidophorus, Eudamonema, Planetetherium, Worlandia, Plagiomene, Ellesmene, Tarkadectes, Tarka, Ekgmowechashala
Family Mixodectidae (Early Palaeocene, unique) e.g. Mixodectes, Dracontolestes
The Infraorder Strepsirrhini includes lemurs, bushbabies and the following North American forms:
Family Adapidae (Early-Middle Eocene) e.g. Mahgarita, Cantius, Copelemur, Smilodectes, Pelycodus, Notharctus, Hesperolemur
The Parvorder Tarsiiformes includes tarsiers and the following North American forms:
Family Carpolestidae (Early Palaeocene-Early Eocene) e.g. Elphidotarsius, Carpodaptes, Carpolestes, Carpocristes
Family Omomyidae (Early-Late Eocene) e.g. Steinius, Omomys, Chumashius, Loveina, Washakius, Shoshonius, Dyseolemur, Macrotarsius, Hemiacodon, Yaquius, Wyomomys, Ageitodendron, Ourayia, Utahia, Stockia, Chipetaia, Uintanius, Rooneyia, Chlororhysis, Arapahovius, Tetonius, Absarokius, Tatmanius, Anaptomorphus, Trogolemur, Sphacorhysis
Wow thank you Loren, for, once again, blowing my mind and putting these things in context.
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