Palæos:		Unit 510: Ungulatomorpha
The Vertebrates		100: Ungulatomorpha

Ungulatomorpha

Zhelestidae & Dinocerata

EUTHERIA
|--INSECTIVORA 
`--+--+--ANAGALIDA   
   |  `--ARCHONTA
   `--+--FERAE
      `--Ungulatomorpha
         |--Zhelestidae
         `--+--Dinocerata
            |--ALTUNGULATA
            `--Eparctocyona
               |--+--Arctostylopida
               |  `--+--Mesonychia
               |     `--CETARTIODACTYLA  
               `--Bulbulodentata
                  |--Hyopsodontidae
                  `--Meridiungulata
                     |--Litopterna
                     `--Notoungulata
                        |--Toxodontia
                        `--Typotheria

Taxa on This Page

1. Dinocerata X
2. Ungulatomorpha
3. Zhelestidae X

Range: from the Late Cretaceous

Phylogeny: Epitheria :::: Ferae + * : Zhelestidae + (Dinocerata + Ungulata).

Characters: premolars simple [d&C00]; small metaconid on p4 [d&C00]; trigonid cusps sharply conical & well separated (metaconid & paraconid fuse in almost all derived groups) [d&C00]; trigonid open lingually [d&C00]; lower molars with at least weak postcingulid [d&C00]; m2 trigonid slightly wider than talonid (reversed in Zhelestids?) [d&C00].

Links: Basal Ungulatomorpha; g00n1a4.pdf; MESOZOIC MAMMALS; ‘basal’ Ungulatomorpha, an internet directory: (Best on the Web -- most of the other links are taken from this one); vol3-p18; Welcome to Adobe GoLive 4; Re: Condylarths (TINGAMARRA REVISITED); Ungulate-Like Mammals from the Late Cretaceous of Uzbekistan and ....; The earliest eutherian mammal

References: de Muizon & Cifelli (2000) [d&C00]. ATW021027. 

Zhelestidae: Aspanlestes, Eoungulatum, Kumsuperus, Parazhelestes, Sorlestes, Taslestes(?), Zhelestes.

Range: Late Cretaceous of Central Asia, Europe & North America. The North American taxa Allostera, Avitotherium, and Gallolestes, if zhelestids, would extend the range into the Early Paleocene. [Av00].

Phylogeny: Ungulatomorpha : (Dinocerata + Ungulata) + *.

Characters: premolars premolars slender, not inflated [d&C00]; some forms with double-rooted (primitive) premolars [d&C00]; upper P3 larger than P4 and may be slightly more molariform [d&C00]; small paraconule may be present on P4 [d&C00]; but P4 (of 5) simple, consisting mostly of paracone and postparacrista, or not at all molariform [d&C00]; P5 small with "waist" created by concavity between protocone and paracone [d&C00]; P5 with small metacone and paraconule [d&C00]; lower p5 with no paraconid & small metaconid [d&C00]; p5 posterior (distal?) wall of trigonid not flattened [d&C00]; p5 with "incipient" talonid basin [d&C00]; molars, upper upper molars generally intermediate between primitive eutherians and ungulates [d&C00]; paracone larger than metacone on M1&2 [d&C00]; metacone distal and (? or?) slightly lingual to paracone [d&C00]; pre- & postcristae present on upper molars [d&C00]; postmetaconular cristae did not enter into interior region of tooth (primitive for eutherians) [d&C00]; but some invasion of interior by preparacristae [d&C00]; postcingulum not thickened and hypocone absent [d&C00]; pre- & postcingula reach protocone at its base [d&C00]; large parastyle shifted lingually, with large mesial projection [d&C00]; parastylar lobe primitive (see Note) [d&C00]; mesostyle absent [d&C00]; trigon basin small and/or shallow [d&C00];pre- & postparaconular cristae sharp & well-developed [d&C00]; lower trigonid cusps conical & well-separated [d&C00]; trigonid open lingually [d&C00]; talonid basin moderately large (?) [d&C00]; talonid basin closed lingually [d&C00]; $ m2 trigonid & talonid of equal width [d&C00]; metaconid only slightly posterior to protoconid [d&C00]; m1 & m2 hypoconulids and entoconids roughly equal in height & size [d&C00]; m3 hypoconulid only slightly expanded [d&C00]; hypoconid largest cusp on talonid [d&C00]; hyoconid forms labial half of talonid & has concave lingual flank [d&C00]; paraconid positioned lingually & somewhat smaller than other major cuspids [d&C00]; paracristid arcuate [d&C00]; cristid obliqua attaches to linguodistal side of protoconid [d&C00]; weak precingulid present [d&C00]; entocristid present and "extends anteriorly and dorsally on the base of the posterior face of the metaconid" [d&C00: 131].

Links: g00n1a4.pdf; Zhelestidae Nesov, 1985; vol3-p18; Nature Japan; 414062aa.

References: Averianov (2000) [Av00]; de Muizon & Cifelli (2000) [d&C00]; Kielan-Jaworowka et al. (2000) [K+00].

Image: Note how far Parazhelestes has progressed toward the ungulate condition. Only one reasonably good skull from a possible zhelestid is known. By contrast with the Parazhelestes dentition, the skull appears strikingly primitive, with a low skull table and narrow jaws.

Note: [1] Zhelestids have the primitive eutherian condition in which "the parastylar lobe is composed of three cusps: 1) the stylocone, which is labial to anterolabial to the paracone and connected to it by the preparacrista; 2) the parastyle, which is just anterior to the paracone; and 3) the preparastyle, which is lingual to the parastyle. The stylocone on the one hand and the parastyle + preparastyle on the other are separated by the parastylar groove, where the shearing action of the protoconid produces an important transverse wear facet." de Muizon & Cifelli (2000: 72) [citations omitted]. [2] may well be paraphyletic assemblage of ungulatomorph stem species. [3] most of the characteristics obtained from de Muizon & Cifelli are plesiomorphic. One of the main objectives of their article was to identify the primitive state of ungulatomorphs, and the authors relied heavily on zhelestids to determine that state. [4] Zhelestids were the first placentals to specialize in herbivory and may have dominated the small herbivore niche in the Late Cretaceous of Central Asia, a semitropical lowland and coastal environment. At the same time, multituberculates occupied the same niche in the more arid, upland environment of Mongolia. [K+00], [Av00]. ATW020210.

Dinocerata: Bathyopsis, Dinoceras, Ditetradon, Eobasileus, Gobiatherium, Jiaoluotherium, Probathyopsis, Prodinoceras, Tetheopsis, Uintatherium; uintatheres.

Range: Late Paleocene to Late Eocene of North America & Asia.

Phylogeny: Ungulatomorpha :: Ungulata + *.

Characters: up to rhino size & 4500 kg (but most forms pig-size); upper incisors usually absent; enlarged canines with flange in lower jaw (size of tusks sexually dimorphic); molars somewhat similar to perissodactyls; V-shape crest on P3-M3 with apex at protocone (see image at right); lower molars with tall trigonid and prominent metalophid (= metacristid); hypolophid (= ?) absent; superficial resemblance to rhinoceros with 0-6 blunt paired facial horns, probably skin-covered (like giraffid artiodactyls); short legs.

Links: Dinocerata Catalogue; Dinocerata; Teeth, Tusks and Tarpits 1 (Knight painting); paleng3 99p308abs; Paleocene mammals of the world; A Pallas nagy lexikona (Hungarian); EOCENO Mamíferos (Spanish); Chronologia Proshessov (Russian); earlyimage; phseb2.html; James Baird Gallery : Search Results: 17 of 24; Uintatherium Skull Replica from Antiquarian Fossils; uintatherium (French); Ice Age Mammals - EnchantedLearning.com.

Images: Right : Eobasileus right P3-M3 from the Burke Museum. Left: unidentified uintatheres and early perissodactyls from the former Field Museum site. Painting by Charles Allen Knight, which I've done my best to digitally restore to something more closely resembling its original color scheme.  ATW011124.

checked ATW040213