Pantodonta is an extinct suborder (or, according to some, an order) of eutherianmammals. These herbivorous mammals were one of the first groups of large mammals to evolve (around 66 million years ago) after the end of the Cretaceous. The last pantodonts died out at the end of the Eocene (around 34 million years ago).
Pantodonta include some of the largest mammals of their time, but were a diversified group, with some primitive members weighing less than 10 kg (22 lb) and the largest more than 500 kg (1,100 lb).[1]
The earliest and most primitive pantodonts, Bemalambda (with a 20 cm (7.9 in) skull probably the size of a dog) and Hypsilolambda, appear in the early Paleocene Shanghuan Formation in China. All more derived families are collectively classified as Eupantodonta. The pantodonts appear in North America in the middle Paleocene, where Coryphodon survived into the middle Eocene. Pantodont teeth have been found in South America (Alcidedorbignya) and Antarctica,[2] and footprints in a coal mine on Svalbard.[3]
The pantodonts varied considerably in size: the small Archaeolambda, of which there is a complete skeleton from the Late Palaeocene of China, was probably arboreal, while the North American, ground sloth-likeBarylambda was massive, slow-moving ("graviportal") and probably browsed on high vegetation.[2]
DentitionEdit
The pantodonts have a primitive dental formula (3.1.4.33.1.4.3) with little or no diastemata. Their most important synapomorphy are the zalambdodont (V-shaped ectoloph opening towards lip) P3–4 and (except in the most primitive families) dilambdodont (W-shaped ectoloph) upper molars. Most pantodonts lacked a hypocone (fourth cusp) and had small conules (additional small cusps). The incisors are small but the canines large, occasionally sabertooth-like. On P3-M3 there is normally an ectoflexus (indentation on the outer side). Asian families can typically be distinguished from the American because their paracone and metacone (bottom of W on side of tongue) tend to be closer together.[1]
The cheek teeth in the lower jaw are also dilambdodont, with broad, high metalophids (posterior crest) and tall metaconid (posterior-interior cusp) with much lower paracristids and small paraconids.[1]
Postcranial skeletonEdit
Pantodonts have plesiomorphic (unaltered) and robust postcranial skeletons. Their five-toed feet are often hoofed with the tarsals similar to those of ungulates, which feature had led to previously suggested ties to arctocyonid "condylarths", but this similarity is now considered primitive.[1]
ClassificationEdit
The pantodonts were previously grouped with the ungulates as amblypods, paenungulates, or arctocyonids, but since McKenna & Bell 1997 they have been allied with the tillodonts and considered to be derived from the cimolestids. The interrelationship within Pantodonta is controversial,[2] but, following McKenna & Bell 1997, it contains about two dozen genera in ten families. Most of the families are known from the Paleocene of either Asia or North America. The pantolambdodontids and coryphodontids survived into the Eocene and the latter are known from across the northern hemisphere.[1] Some dental features can possibly link the most primitive pantodonts to the palaeoryctids, a group of small and insectivorous mammals that evolved during the Cretaceous.[2] Recently a close relationship with Periptychidae has been suggested.[4] This would make pantodonts crown-group ungulateplacentals and not related to cimolestids at all.
Genera from North America tended to be large and robust, starting with Pantolambda and Caenolambda in the Middle Paleocene epoch, and later in the epoch started to get larger, with Barylambda as the largest Paleocene form of pantodont. However, Asian forms, such as Archaeolambda, tended to be thinner and less robust, around the size of a medium-sized dog. Only later in the Eocene, with Hypercoryphodon, did Asian pantodonts get large and robust.
Cope, Edward Drinker (1873). "On the short footed Ungulata of the Eocene of Wyoming". Proceedings of the American Philosophical Society. 13: 38–74. Retrieved 1 July 2013.
Kemp, Tom S. (2005). The Origin and Evolution of Mammals. Oxford University Press. ISBN978-0198507611. OCLC 56652579.
McKenna, Malcolm C.; Bell, Susan K. (1997). Classification of Mammals Above the Species Level. New York: Columbia University Press. ISBN978-0231110136. OCLC 37345734.
Rose, Kenneth David (2006). The beginning of the age of mammals. Baltimore: JHU Press. ISBN978-0801884726.
"†PANTODONTA - pantodonts". After McKenna & Bell (1997), and Alroy (2002). Retrieved 3 November 2013.
^"Fossil Arctic animal tracks point to climate risks". Reuters. April 25, 2007. Retrieved 1 July 2013.
^Halliday, Thomas J.D.; Upchurch, Paul; Goswami, Anjali (February 2017). "Resolving the relationships of Paleocene placental mammals" (PDF). Biological Reviews. 92 (1): 521–55–. doi:10.1111/brv.12242. PMC6849585. PMID 28075073.
External linksEdit
Paleocene-Mammals
August 27, 2023
pantodonta, extinct, suborder, according, some, order, eutherian, mammals, these, herbivorous, mammals, were, first, groups, large, mammals, evolve, around, million, years, after, cretaceous, last, pantodonts, died, eocene, around, million, years, temporal, ra. Pantodonta is an extinct suborder or according to some an order of eutherian mammals These herbivorous mammals were one of the first groups of large mammals to evolve around 66 million years ago after the end of the Cretaceous The last pantodonts died out at the end of the Eocene around 34 million years ago PantodontaTemporal range Paleocene Eocene 65 34 Ma PreꞒ Ꞓ O S D C P T J K Pg NBarylambdaScientific classificationDomain EukaryotaKingdom AnimaliaPhylum ChordataClass MammaliaOrder CimolestaSuborder PantodontaCope 1873SubgroupsWangliidae Alcidedorbignya Bemalambdoidea Bemalambdidae Harpyodidae Coryphodontoidea Coryphodontidae Pantolambdoidea Barylambdidae Cyriacotheriidae Pantolambdidae Pantolambdodontidae Pastoralodontidae TitanoideidaePantodonta include some of the largest mammals of their time but were a diversified group with some primitive members weighing less than 10 kg 22 lb and the largest more than 500 kg 1 100 lb 1 The earliest and most primitive pantodonts Bemalambda with a 20 cm 7 9 in skull probably the size of a dog and Hypsilolambda appear in the early Paleocene Shanghuan Formation in China All more derived families are collectively classified as Eupantodonta The pantodonts appear in North America in the middle Paleocene where Coryphodon survived into the middle Eocene Pantodont teeth have been found in South America Alcidedorbignya and Antarctica 2 and footprints in a coal mine on Svalbard 3 Contents 1 Description 1 1 Dentition 1 2 Postcranial skeleton 2 Classification 3 Timeline of genera 4 References 5 Footnotes 6 External linksDescription Edit Undescribed specimenThe pantodonts varied considerably in size the small Archaeolambda of which there is a complete skeleton from the Late Palaeocene of China was probably arboreal while the North American ground sloth like Barylambda was massive slow moving graviportal and probably browsed on high vegetation 2 Dentition Edit The pantodonts have a primitive dental formula 3 1 4 3 3 1 4 3 with little or no diastemata Their most important synapomorphy are the zalambdodont V shaped ectoloph opening towards lip P3 4 and except in the most primitive families dilambdodont W shaped ectoloph upper molars Most pantodonts lacked a hypocone fourth cusp and had small conules additional small cusps The incisors are small but the canines large occasionally sabertooth like On P3 M3 there is normally an ectoflexus indentation on the outer side Asian families can typically be distinguished from the American because their paracone and metacone bottom of W on side of tongue tend to be closer together 1 The cheek teeth in the lower jaw are also dilambdodont with broad high metalophids posterior crest and tall metaconid posterior interior cusp with much lower paracristids and small paraconids 1 Postcranial skeleton Edit Pantodonts have plesiomorphic unaltered and robust postcranial skeletons Their five toed feet are often hoofed with the tarsals similar to those of ungulates which feature had led to previously suggested ties to arctocyonid condylarths but this similarity is now considered primitive 1 Classification EditThe pantodonts were previously grouped with the ungulates as amblypods paenungulates or arctocyonids but since McKenna amp Bell 1997 they have been allied with the tillodonts and considered to be derived from the cimolestids The interrelationship within Pantodonta is controversial 2 but following McKenna amp Bell 1997 it contains about two dozen genera in ten families Most of the families are known from the Paleocene of either Asia or North America The pantolambdodontids and coryphodontids survived into the Eocene and the latter are known from across the northern hemisphere 1 Some dental features can possibly link the most primitive pantodonts to the palaeoryctids a group of small and insectivorous mammals that evolved during the Cretaceous 2 Recently a close relationship with Periptychidae has been suggested 4 This would make pantodonts crown group ungulate placentals and not related to cimolestids at all Genera from North America tended to be large and robust starting with Pantolambda and Caenolambda in the Middle Paleocene epoch and later in the epoch started to get larger with Barylambda as the largest Paleocene form of pantodont However Asian forms such as Archaeolambda tended to be thinner and less robust around the size of a medium sized dog Only later in the Eocene with Hypercoryphodon did Asian pantodonts get large and robust Life reconstruction of Barylambda faberi Life reconstruction of Pantolambda bathmodon Restoration of Titanoides primaevusTimeline of genera EditReferences EditCope Edward Drinker 1873 On the short footed Ungulata of the Eocene of Wyoming Proceedings of the American Philosophical Society 13 38 74 Retrieved 1 July 2013 Kemp Tom S 2005 The Origin and Evolution of Mammals Oxford University Press ISBN 978 0198507611 OCLC 56652579 McKenna Malcolm C Bell Susan K 1997 Classification of Mammals Above the Species Level New York Columbia University Press ISBN 978 0231110136 OCLC 37345734 Rose Kenneth David 2006 The beginning of the age of mammals Baltimore JHU Press ISBN 978 0801884726 PANTODONTA pantodonts After McKenna amp Bell 1997 and Alroy 2002 Retrieved 3 November 2013 Footnotes Edit a b c d e Rose 2006 p 114 a b c d Kemp 2005 pp 238 40 Fossil Arctic animal tracks point to climate risks Reuters April 25 2007 Retrieved 1 July 2013 Halliday Thomas J D Upchurch Paul Goswami Anjali February 2017 Resolving the relationships of Paleocene placental mammals PDF Biological Reviews 92 1 521 55 doi 10 1111 brv 12242 PMC 6849585 PMID 28075073 External links EditPaleocene Mammals Retrieved from https en wikipedia org w index php title Pantodonta amp oldid 1162494931, wikipedia, wiki, book, books, library,
