165:, likely grazed on low-lying vegetation and microwear patterns show that their diet contained an abrasive material, such as grit or silica. Grasses had evolved by the Late Cretaceous, but were not particularly common, so this study concluded that grass probably did not play a major component in the hadrosaur's diet.
156:
Most importantly, evidence has shown, that the development of hypsodonty in
Cenozoic mammals is out of sync with the flourishing of grasslands both in North America and South America, where grasslands spread 10 million years earlier. Observations of this temporal discontinuity between the spread
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from the Late
Oligocene Salla Beds of Bolivia showed shearing movements are associated with a diet rich in tough plants, not necessarily grasses. Hence the relationship between high-crowned mammals and the source of tooth wear in the fossil record may not be straightforward and the spread of
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that switched from browsing diets to grazing diets. Grass contains silica-rich phytoliths (abrasive granules), which wear away dental tissue more quickly. So the spread of grasslands was linked to the development of high-crowned (hypsodont) teeth in grazers.
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epochs (25 million years), the continental climate became favorable to the evolution of grasslands. Existing forest biomes declined and grasslands became much more widespread. The grasslands provided a new
143:
More recent examination of mammalian teeth suggests that it is the open, gritty habitat and not the grass itself which is linked to diet changes. Analysis of dental microwear patterns of hypsodont
127:. In 2008 Mendoza and Palmqvist determined the relative importance of grass consumption and open habitat foraging in the development of hypsodont teeth using a dataset of 134 species of
412:
Billet, Blondel, and Muizon (2009), "Dental microwear analysis of notoungulates (Mammalia) from Salla (Late
Oligocene, Bolivia) and discussion on their precocious hypsodonty",
446:
111:, rhinoceroses) from the early to middle Miocene of North America, which had been classically linked to the spread of grasslands. She showed habitats dominated by
48:
Since the morphology of the hypsodont tooth is suited to a more abrasive diet, hypsodonty was thought to have evolved concurrently with the spread of
193:, has hypsodont dentition. A mammal may have exclusively hypsodont molars or have a mix of dentitions. Hypsodont dentition is characterized by:
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grasslands and the development of hypsodonty in mammals is also supported by earlier evidence of hypsodonty in dinosaurs. For example,
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In 2006 Strömberg examined the independent acquisition of high-crowned cheek teeth (hypsodonty) in several ungulate lineages (e.g.,
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135:. The results suggested that high-crowned teeth represent are adapted for a particular feeding environment, not diet preference.
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grasslands in South
America, traditionally linked with the development of notoungulate hypsodonty, was called into question.
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256:(2012). "Grit not grass: Concordant patterns of early origin of hypsodonty in Great Plains ungulates and Glires".
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72:(65-55 million years ago), leaving behind thick marine deposits and relatively flat terrain. During the
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Hypsodonty is observed both in the fossil record and the modern world. It is a characteristic of large
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375:"Hypsodonty in ungulates: an adaptation for grass consumption or for foraging in open habitat?"
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123:(≥21.9 Million years ago), at least 4 million years prior to the emergence of hypsodonty in
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24:, particularly in New World mammals. The hypothesis is that the ingestion of gritty
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which covers the entire length of the body and likewise extends past the gum line
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Period (145-66 million years ago), the Great Plains were covered by a shallow
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330:"Evolution of hypsodonty in equids: testing a hypothesis of adaptation"
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177:(equids) as well as subspecies level specialization. For example, the
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is an evolutionary hypothesis that explains the evolution of
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10.1666/0094-8373(2006)32[236:eohiet]2.0.co;2
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Jardine, Phillip E.; Janis, Christine M.; Sahney, Sarda;
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289:"Observations on Evolutionary Rates in Hypsodonty"
414:Palaeogeography, Palaeoclimatology, Palaeoecology
258:Palaeogeography, Palaeoclimatology, Palaeoecology
479:(May 2007). "South America's Missing Mammals".
115:(cool-season grasses) were established in the
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8:
460:"Hadrosaur chowdown — grind, grind, grind",
445:: CS1 maint: multiple names: authors list (
373:Mendoza, M.; Palmqvist, P. (February 2008).
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207:surface adapted for crushing and grinding
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7:
189:, lophodont cheek teeth whereas the
44:Traditional co-evolution hypothesis
306:10.1111/j.1558-5646.1947.tb02711.x
14:
501:10.1038/scientificamerican0507-68
328:Caroline A. E. Strömberg (2006).
64:which began to recede during the
475:Flynn, John J.; Wyss, André R.;
394:10.1111/j.1469-7998.2007.00365.x
230:into the thick layer of dentine
94:Modern evolutionary hypothesis
1:
169:Modern Examples of Hypsodonty
40:, as was previously thought.
434:10.1016/j.palaeo.2009.01.004
274:10.1016/j.palaeo.2012.09.001
226:The cementum and the enamel
85:for mammals, including many
32:tooth development, not the
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18:grit, not grass hypothesis
213:both above and below the
161:, a group of herbivorous
28:is the primary driver of
522:Kwan, Paul W.L. (2007).
287:Stirton, R. A. (1947).
62:Western Interior Seaway
152:Temporal discontinuity
556:Biological hypotheses
36:-rich composition of
551:Evolution of mammals
546:Evolutionary biology
524:"Digestive system I"
117:Central Great Plains
529:. Tufts University.
493:2007SciAm.296e..68F
481:Scientific American
426:2009PPP...274..114B
266:2012PPP...365....1J
179:Sumatran rhinoceros
477:Charrier, Reynaldo
382:Journal of Zoology
254:Benton, Michael J.
203:A rough, flattish
22:high-crowned teeth
260:. 365–366: 1–10.
191:Indian rhinoceros
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462:Associated Press
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133:perissodactyls
119:by early late
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99:Early evidence
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145:notoungulates
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52:. During the
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487:(5): 68–75.
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337:Paleobiology
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323:
296:
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142:
129:artiodactyls
102:
47:
17:
15:
60:called the
540:Categories
235:References
228:invaginate
187:brachydont
185:both have
159:hadrosaurs
139:Morphology
121:Arikareean
113:C3 grasses
58:inland sea
54:Cretaceous
50:grasslands
293:Evolution
163:dinosaurs
87:ungulates
70:Paleocene
30:hypsodont
509:17500416
441:citation
357:12338144
315:87532435
215:gingival
211:Cementum
205:occlusal
181:and the
105:camelids
78:Pliocene
489:Bibcode
422:Bibcode
262:Bibcode
125:Equidae
74:Miocene
68:to the
507:
464:, 2009
355:
313:
221:Enamel
175:clades
109:equids
34:silica
527:(PDF)
378:(PDF)
353:S2CID
333:(PDF)
311:S2CID
199:teeth
83:niche
38:grass
505:PMID
447:link
217:line
131:and
76:and
26:soil
16:The
497:doi
485:296
430:doi
418:274
390:doi
386:274
345:doi
301:doi
270:doi
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443:}}
439:{{
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242:^
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