upcScavenger » Mammal Suborders » Wiki: Pantodonta

Pantodonta

( Mammal Suborders )

Description

Dentition
Postcranial skeleton

Classification
Timeline of genera
References
Footnotes
External links

C O N T E N T S

Colorpaleocene Paleocene Pantodonts Till

Rank: 100%

Wiki
Comments
Media

Pantodonta is an extinct suborder (or, according to some, an order) of . These herbivorous mammals were one of the first groups of large mammals to evolve (around 66 million years ago) after the K-T boundary. 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 and the largest more than .

The earliest and most primitive pantodonts, Bemalambda (with a 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, and footprints in a coal mine on Svalbard.

Description

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 Barylambda was massive, slow-moving ("") and probably browsed on high vegetation.

Dentition

The pantodonts have a primitive dental formula () with little or no diastemata. Their most important synapomorphy are the (V-shaped ectoloph opening towards lip) P^3–4 and (except in the most primitive families) (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.

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.

Postcranial skeleton

Pantodonts have Plesiomorphy (unaltered) and robust postcranial skeletons. Their five-toed feet are often hoofed with the tarsals similar to those of , which feature had led to previously suggested ties to Arctocyonidae "", but this similarity is now considered primitive.

Classification

The pantodonts were previously grouped with the ungulates as Amblypoda, Paenungulata, or Arctocyonidae, but since they have been allied with the Tillodonta and considered to be derived from the Cimolestidae. The interrelationship within Pantodonta is controversial, but, following , 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. Some dental features can possibly link the most primitive pantodonts to the Palaeoryctidae, a group of small and insectivorous mammals that evolved during the Cretaceous. Recently a close relationship with Periptychidae has been suggested. This would make pantodonts crown-group Ungulata Placentalia 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.

File:Barylambda NT small.jpg|Life reconstruction of Barylambda faberi File:Pantolambda NT copy.jpg|Life reconstruction of Pantolambda bathmodon File:Titanoides.jpg|Restoration of Titanoides primaevus

Timeline of genera

ImageSize = width:850px height:auto barincrement:15px PlotArea = left:10px bottom:50px top:10px right:10px

Period = from:-66 till:-23.03 TimeAxis = orientation:horizontal ScaleMajor = unit:year increment:10 start:-60 ScaleMinor = unit:year increment:1 start:-66 TimeAxis = orientation:hor AlignBars = justify

Colors =

#legends
 id:CAR	value:claret
 id:ANK 	value:rgb(0.4,0.3,0.196)
 id:HER	value:teal
 id:HAD	value:green
 id:OMN	value:blue
 id:black      value:black
 id:white      value:white
 id:paleogene  value:rgb(0.99,0.6,0.32)
 id:paleocene  value:rgb(0.99,0.65,0.37)
 id:eocene     value:rgb(0.99,0.71,0.42)
 id:oligocene  value:rgb(0.99,0.75,0.48)

BarData=

bar:eratop
bar:space
bar:periodtop
bar:space
bar:NAM1
bar:NAM2
bar:NAM3
bar:NAM4
bar:NAM5
bar:NAM6
bar:space
bar:period
bar:space
bar:era

PlotData=

align:center textcolor:black fontsize:M mark:(line,black) width:25
shift:(7,-4)

bar:periodtop
from: -66   till:  -56    color:paleocene  text:[[Paleocene]]
from: -56   till:  -33.9    color:eocene  text:[[Eocene]]
from: -33.9   till:  -23.03    color:oligocene  text:[[Oligocene]]

bar:eratop
from: -66   till:  -23.03    color:paleogene  text:[[Paleogene]]

PlotData=

align:left fontsize:M mark:(line,white) width:5 anchor:till align:left

color:paleocene bar:NAM1  from:-64	till:-61	text:	[[Alcidedorbignya]]
color:paleocene bar:NAM2  from:-63	till:-57	text:	[[Pantolambda]]
color:paleocene bar:NAM3  from:-60	till:-50	text:	[[Barylambda]]
color:paleocene bar:NAM4  from:-59	till:-56	text:	[[Titanoides]]
color:paleocene bar:NAM5  from:-57	till:-46	text:	[[Coryphodon]]
color:eocene    bar:NAM6  from:-37	till:-34	text:	[[Hypercoryphodon]]

PlotData=

align:center textcolor:black fontsize:M mark:(line,black) width:25

bar:period
from: -66   till:  -56    color:paleocene  text:[[Paleocene]]
from: -56   till:  -33.9    color:eocene  text:[[Eocene]]
from: -33.9   till:  -23.03    color:oligocene  text:[[Oligocene]]

bar:era
from: -66   till:  -23.03    color:paleogene  text:[[Paleogene]]

Tom S. Kemp (2025). 9780198507611, Oxford University Press. ISBN 9780198507611
(1997). 9780231110136, Columbia University Press. ISBN 9780231110136
Kenneth David Rose (2025). 9780801884726, JHU Press. . ISBN 9780801884726