fbpx
Wikipedia

Maiasaura

September 01, 2023

Maiasaura (from the Greek μαῖα, meaning "good mother" and σαύρα, the feminine form of saurus, meaning "reptile") is a large herbivorous saurolophine hadrosaurid ("duck-billed") dinosaur genus that lived in the area currently covered by the state of Montana and the province of Alberta, Canada,[1] in the Upper Cretaceous Period (mid to late Campanian), about 76.7 million years ago.[2]

Maiasaura
Temporal range: Late Cretaceous (Campanian), 76.7 Ma
↓
Mounted cast, Brussels Natural History Museum
Scientific classification
Domain: Eukaryota
Kingdom: Animalia
Phylum: Chordata
Clade: Dinosauria
Clade: †Ornithischia
Clade: †Ornithopoda
Family: †Hadrosauridae
Subfamily: †Saurolophinae
Tribe: †Brachylophosaurini
Genus: †Maiasaura
Horner & Makela, 1979
Type species
†Maiasaura peeblesorum
Horner & Makela, 1979
Synonyms

The first remains of Maiasaura were discovered in 1978 by Bynum, Montana resident Laurie Trexler. The genus was named in 1979. The name refers to the find of nests with eggs, embryos and young animals, in a nesting colony. These showed that Maiasaura fed its young while they were in the nest, the first time such evidence was obtained for a dinosaur. Hundreds of bones of Maiasaura have been dug up.

Maiasaura was about 9 metres (30 ft) long. Young animals walked on their hind legs, adults on all fours. Maiasaura was probably closely related to Brachylophosaurus.

Description Edit

 
Skull cast, Royal Ontario Museum
 
Size comparison with human

Maiasaura were large, attaining a maximum known length of about 9 metres (30 ft). They had a large beak typical of hadrosaurids, and thick noses. They had a small, spiky crest in front of the eyes. This crest may have been used in headbutting contests between males during the breeding season.[3] Its body mass is measured approximately up to 4 metric tons (4.4 short tons).[4]

Maiasaura were herbivorous. They were capable of walking both on two (bipedal) or four (quadrupedal) legs. Studies of the stress patterns of healed bones show that young juveniles under four years old walked mainly bipedal, switching to a mainly quadrupedal style of walking when they grew larger.[5] Maiasaura, like most other hadrosaurs, possessed little in the way of obvious weaponry, though likely could defend themselves with kicks, stomps, or their muscular tails. It is likely that they primarily resorted to fleeing in the face of danger, using the vast sizes of their herds to be less likely to be targeted. Herds were extremely large and could have comprised as many as 10,000 individuals.[3] Maiasaura lived in an inland habitat.[6]

Discovery Edit

 
Reconstructed cast by Jack Horner of a Maiasaura emerging from its egg

A skull of Maiasaura, specimen PU 22405 (now in the collections of the Yale Peabody Museum of Natural History as YPM PU 22405 following the transfer of the Princeton University vertebrate paleontology collections), was discovered by Laurie Trexler in 1979 and described by dinosaur paleontologists Jack Horner and Robert Makela as the holotype of a new species. They named the type species Maiasaura peeblesorum. The generic name refers to the Greek goddess Maia, the "Good Mother"; to emphasise this, they used the feminine form of saurus: saura. The specific name honours the families of John and James Peebles, on whose land the finds were made.[7] The generic name refers to Marion Brandvold's discovery in 1978 of a nest with remains of eggshells and babies too large to be hatchlings. These discoveries led to others, and the area became known as "Egg Mountain", in rocks of the Two Medicine Formation near Choteau in western Montana. This was the first proof of giant dinosaurs raising and feeding their young.[3]

Over 200 specimens, in all age ranges, have been found.[8] The announcement of the discovery of Maiasaura attracted renewed scientific interest to the Two Medicine Formation and many other new kinds of dinosaurs were discovered as a result of the increased attention.[9] Choteau Maiasaura remains are found in higher strata than their Two Medicine River counterparts.[10]

Classification Edit

 
Cast of a juvenile skeleton
 
Life restorations of an adult and juvenile

The following cladogram of hadrosaurid relationships was published in 2013 by Albert Prieto-Márquez et al.:[11]

Palaeobiology Edit

Maiasaura lived in herds and it raised its young in nesting colonies. The nests in the colonies were packed closely together, like those of modern seabirds, with the gap between the nests being around 7 metres (23 ft); less than the length of the adult animal.[12] The nests were made of earth and contained 30 to 40 eggs laid in a circular or spiral pattern. The eggs were about the size of ostrich eggs.[3]

The eggs were incubated by the heat resulting from rotting vegetation placed into the nest by the parents, rather than a parent sitting on the nest. Upon hatching, fossils of baby Maiasaura show that their legs were not fully developed and thus they were incapable of walking. Fossils also show that their teeth were partly worn, which means that the adults brought food to the nest.[3]

 
Reconstruction of a nest with eggs

The hatchlings grew from a size of 41 to 147 centimetres (16 to 58 in) long in the span of their first year. At this point, or perhaps after another year, the animal left the nest. This high rate of growth may be evidence of warm bloodedness. The hatchlings had different facial proportions from the adults, with larger eyes and a shorter snout.[3] These features are associated with cuteness, and commonly elicit care from parents in animals dependent on their parents for survival during the early stages of life.

Studies led by Holly Woodward, Jack Horner, Freedman Fowler et al. have given insight into the life history of Maiasaura, resulting in what is perhaps the most detailed life history of any dinosaur known, and to which all others can be compared. From a sample of fifty individual Maiasaura tibiae, it was found that Maiasaurs had a mortality rate of about 89.9% in their first year of life. If the animals survived their second year, their mortality rate would drop to 12.7%. The animals would spend their next six years maturing and growing. Sexual maturity was found to occur in their third year, while skeletal maturity was attained at eight years of age. In their eighth year and beyond, the mortality rate for Maiasaura would spike back to around 44.4%. The studies that followed also found that Maiasaurs were primarily bipedal as juveniles, and switched to a more quadrupedal stance as they aged. It was also found that Maiasaura also included rotting wood in its diet, as well that its environment had a long, dry season prone to drought. The results of the study were published in the journal Palaeobiology on September 3, 2015.[13][14]

Diet Edit

A paper from 2007 showed that Maiasaura had a diet consisting of fibrous plants, wood, rotting wood, tree bark, leaves, branches, ferns, angiosperms and possibly grasses. This would imply that Maiasaura was both a browser and a grazer.[15][16]

Sexual dimorphism Edit

Studies of Maiasaura by Saitta et al., suggest that one sex was roughly 45% larger than the other according to the mathematical analysis known as size statistics. However, it cannot be ascertained at this time whether the larger gender was male or female.[17][18]

Palaeoecology Edit

 
Illustration of a herd of Maiasaura walking along a creekbed, as found in the semi-arid Two Medicine Formation fossil bed. This region was characterized by volcanic ash layers and conifer, fern and horsetail vegetation.

Maiasaura is a characteristic fossil of the middle portion (lithofacies 4) of the Two Medicine Formation, dated to about 76.4 million years ago.[2] Maiasaura lived alongside the troodontid Stenonychosaurus (formerly Troodon) and the basal ornithopod Orodromeus, as well as the dromaeosaurid Bambiraptor and the tyrannosaur Daspletosaurus.[2] Another species of hadrosaurids, referable to the genus Hypacrosaurus, coexisted with Maiasaura for some time, as Hypacrosaurus remains have been found lower in the Two Medicine Formation than was earlier known.[19] The discovery of an additional hadrosaurid, Gryposaurus latidens, in the same range as Maiasaura has shown that the border between hypothesized distinct faunas in the upper and middle is less distinct than once thought.[19] There seems to be a major diversification in ornithischian taxa after the appearance of Maiasaura within the Two Medicine Formation.[19] The thorough examination of strata found along the Two Medicine River (which exposes the entire upper half of the Two Medicine Formation) indicates that the apparent diversification was a real event rather than a result of preservational biases.[19] While Maiasaura has historically been associated with the Two Medicine formation ceratopsid Einiosaurus in a single fauna, this is inaccurate, as Maiasaura is known exclusively from older strata.[20]

In the Oldman Formation of Alberta, Maiasaura lived alongside the ceratopsians Albertaceratops, Anchiceratops, Chasmosaurus, Coronosaurus, and Wendiceratops, as well as the dromaeosaurids Dromaeosaurus, Saurornitholestes, and Hesperonychus, the tyrannosaurid Daspletosaurus, the orodromine thescelosaurid Albertadromeus, the pachycephalosaurs Foraminacephale and Hanssuesia, the ornithomimid Struthiomimus, the other hadrosaurids Brachylophosaurus, Corythosaurus, and Parasaurolophus, and the ankylosaurid Scolosaurus.[1]

See also Edit

Footnotes Edit

  1. ^ a b McFeeters, Bradley D.; Evans, David C.; Ryan, Michael J.; Maddin, Hillary C. (2021-03-01). "First occurrence of Maiasaura (Dinosauria, Hadrosauridae) from the Upper Cretaceous Oldman Formation of southern Alberta, Canada". Canadian Journal of Earth Sciences. 58 (3): 286–296. Bibcode:2021CaJES..58..286M. doi:10.1139/cjes-2019-0207. ISSN 0008-4077. S2CID 233851376.
  2. ^ a b c Horner, J. R., Schmitt, J. G., Jackson, F., & Hanna, R. (2001). Bones and rocks of the Upper Cretaceous Two Medicine-Judith River clastic wedge complex, Montana. In Field trip guidebook, Society of Vertebrate Paleontology 61st Annual Meeting: Mesozoic and Cenozoic Paleontology in the Western Plains and Rocky Mountains. Museum of the Rockies Occasional Paper (Vol. 3, pp. 3-14).
  3. ^ a b c d e f "Maiasaura," Dodson, et al. (1994); pages 116-117.
  4. ^ Wosik, M.; Chiba, K.; Therrien, F.; Evans, D.C. (2020). "Testing Size–frequency Distributions As a Method of Ontogenetic Aging: A Life-history Assessment of Hadrosaurid Dinosaurs from the Dinosaur Park Formation of Alberta, Canada, with Implications for Hadrosaurid Paleoecology". Paleobiology. 46 (3): 379–404. doi:10.1017/pab.2020.2. S2CID 221666530.
  5. ^ Cubo, Jorge; Woodward, Holly; Wolff, Ewan; Horner, John R. (2015). "First Reported Cases of Biomechanically Adaptive Bone Modeling in Non-Avian Dinosaurs". PLOS ONE. 10 (7): e0131131. Bibcode:2015PLoSO..1031131C. doi:10.1371/journal.pone.0131131. PMC 4495995. PMID 26153689.
  6. ^ "Judithian Climax," Lehman (2001); page 315.
  7. ^ Horner, J.R.; Makela, R. (1979). "Nest of juveniles provides evidence of family structure among dinosaurs". Nature. 282 (5736): 296–298. Bibcode:1979Natur.282..296H. doi:10.1038/282296a0. S2CID 4370793.
  8. ^ Horner and Gorman (1988).
  9. ^ "Introduction," Trexler (2001); pages 299-300.
  10. ^ "Faunal Turnover, Migration, and Evolution," Trexler (2001); page 304.
  11. ^ Prieto-Márquez, A.; Wagner, J.R. (2013). "A new species of saurolophine hadrosaurid dinosaur from the Late Cretaceous of the Pacific coast of North America". Acta Palaeontologica Polonica. 58 (2): 255–268. doi:10.4202/app.2011.0049.
  12. ^ Palmer (1999); page 148.
  13. ^ "Largest dinosaur population growth study ever shows how Maiasaura lived and died: Decades of research on Montana's state fossil -- the 'good mother lizard' Maiasaura peeblesorum -- has resulted in the most detailed life history of any dinosaur known".
  14. ^ Woodward, Holly N.; Freedman Fowler, Elizabeth A.; Farlow, James O.; Horner, John R. (2015). "Maiasaura, a model organism for extinct vertebrate population biology: A large sample statistical assessment of growth dynamics and survivorship". Paleobiology. 41 (4): 503–527. doi:10.1017/pab.2015.19. S2CID 85902880.
  15. ^ Chin, Karen (1 September 2007). "The Paleobiological Implications of Herbivorous Dinosaur Coprolites from the Upper Cretaceous Two Medicine Formation of Montana: Why Eat Wood?". PALAIOS. 22 (5): 554–566. Bibcode:2007Palai..22..554C. doi:10.2110/palo.2006.p06-087r. JSTOR 27670451. S2CID 86197149. Retrieved 29 August 2020.
  16. ^ ""The Best of all Mothers" Maiasaura peeblesorum". bioweb.uwlax.edu/. University of Wisconsin-La Crosse. Retrieved 22 March 2021.
  17. ^ "Using math to examine the sex differences in dinosaurs".
  18. ^ "Statistical analysis reveals differences between dinosaur sexes".
  19. ^ a b c d "Faunal Turnover, Migration, and Evolution," Trexler (2001); page 306.
  20. ^ Sullivan, R. M.; Lucas, S. G. (2006). "The Kirtlandian land-vertebrate "age"–faunal composition, temporal position and biostratigraphic correlation in the nonmarine Upper Cretaceous of western North America". New Mexico Museum of Natural History and Science Bulletin. 35: 7–29.

References Edit

 
Wikimedia Commons has media related to Maiasaura.
  • Dodson, Peter & Britt, Brooks & Carpenter, Kenneth & Forster, Catherine A. & Gillette, David D. & Norell, Mark A. & Olshevsky, George & Parrish, J. Michael & Weishampel, David B. The Age of Dinosaurs. Publications International, LTD. p. 116-117. ISBN 0-7853-0443-6.
  • Horner, Jack and Gorman, James. (1988). Digging Dinosaurs: The Search that Unraveled the Mystery of Baby Dinosaurs, Workman Publishing Co.
  • Lehman, T. M., 2001, Late Cretaceous dinosaur provinciality: In: Mesozoic Vertebrate Life, edited by Tanke, D. H., and Carpenter, K., Indiana University Press, pp. 310–328.
  • Palmer, D., ed. (1999). The Marshall Illustrated Encyclopedia of Dinosaurs and Prehistoric Animals. London: Marshall Editions. p. 148. ISBN 1-84028-152-9.
  • Trexler, D., 2001, Two Medicine Formation, Montana: geology and fauna: In: Mesozoic Vertebrate Life, edited by Tanke, D. H., and Carpenter, K., Indiana University Press, pp. 298–309.

September 01, 2023
maiasaura, from, greek, μαῖα, meaning, good, mother, σαύρα, feminine, form, saurus, meaning, reptile, large, herbivorous, saurolophine, hadrosaurid, duck, billed, dinosaur, genus, that, lived, area, currently, covered, state, montana, province, alberta, canada. Maiasaura from the Greek maῖa meaning good mother and sayra the feminine form of saurus meaning reptile is a large herbivorous saurolophine hadrosaurid duck billed dinosaur genus that lived in the area currently covered by the state of Montana and the province of Alberta Canada 1 in the Upper Cretaceous Period mid to late Campanian about 76 7 million years ago 2 MaiasauraTemporal range Late Cretaceous Campanian 76 7 Ma PreꞒ Ꞓ O S D C P T J K Pg N Mounted cast Brussels Natural History MuseumScientific classificationDomain EukaryotaKingdom AnimaliaPhylum ChordataClade DinosauriaClade OrnithischiaClade OrnithopodaFamily HadrosauridaeSubfamily SaurolophinaeTribe BrachylophosauriniGenus MaiasauraHorner amp Makela 1979Type species Maiasaura peeblesorumHorner amp Makela 1979SynonymsBrachylophosaurus peeblesorum Horner amp Makela 1979 Paul 2010The first remains of Maiasaura were discovered in 1978 by Bynum Montana resident Laurie Trexler The genus was named in 1979 The name refers to the find of nests with eggs embryos and young animals in a nesting colony These showed that Maiasaura fed its young while they were in the nest the first time such evidence was obtained for a dinosaur Hundreds of bones of Maiasaura have been dug up Maiasaura was about 9 metres 30 ft long Young animals walked on their hind legs adults on all fours Maiasaura was probably closely related to Brachylophosaurus Contents 1 Description 2 Discovery 3 Classification 4 Palaeobiology 4 1 Diet 4 2 Sexual dimorphism 5 Palaeoecology 6 See also 7 Footnotes 8 ReferencesDescription Edit nbsp Skull cast Royal Ontario Museum nbsp Size comparison with humanMaiasaura were large attaining a maximum known length of about 9 metres 30 ft They had a large beak typical of hadrosaurids and thick noses They had a small spiky crest in front of the eyes This crest may have been used in headbutting contests between males during the breeding season 3 Its body mass is measured approximately up to 4 metric tons 4 4 short tons 4 Maiasaura were herbivorous They were capable of walking both on two bipedal or four quadrupedal legs Studies of the stress patterns of healed bones show that young juveniles under four years old walked mainly bipedal switching to a mainly quadrupedal style of walking when they grew larger 5 Maiasaura like most other hadrosaurs possessed little in the way of obvious weaponry though likely could defend themselves with kicks stomps or their muscular tails It is likely that they primarily resorted to fleeing in the face of danger using the vast sizes of their herds to be less likely to be targeted Herds were extremely large and could have comprised as many as 10 000 individuals 3 Maiasaura lived in an inland habitat 6 Discovery Edit nbsp Reconstructed cast by Jack Horner of a Maiasaura emerging from its eggA skull of Maiasaura specimen PU 22405 now in the collections of the Yale Peabody Museum of Natural History as YPM PU 22405 following the transfer of the Princeton University vertebrate paleontology collections was discovered by Laurie Trexler in 1979 and described by dinosaur paleontologists Jack Horner and Robert Makela as the holotype of a new species They named the type species Maiasaura peeblesorum The generic name refers to the Greek goddess Maia the Good Mother to emphasise this they used the feminine form of saurus saura The specific name honours the families of John and James Peebles on whose land the finds were made 7 The generic name refers to Marion Brandvold s discovery in 1978 of a nest with remains of eggshells and babies too large to be hatchlings These discoveries led to others and the area became known as Egg Mountain in rocks of the Two Medicine Formation near Choteau in western Montana This was the first proof of giant dinosaurs raising and feeding their young 3 Over 200 specimens in all age ranges have been found 8 The announcement of the discovery of Maiasaura attracted renewed scientific interest to the Two Medicine Formation and many other new kinds of dinosaurs were discovered as a result of the increased attention 9 Choteau Maiasaura remains are found in higher strata than their Two Medicine River counterparts 10 Classification Edit nbsp Cast of a juvenile skeleton nbsp Life restorations of an adult and juvenileThe following cladogram of hadrosaurid relationships was published in 2013 by Albert Prieto Marquez et al 11 Saurolophinae Brachylophosaurini Acristavus gagstarsoniBrachylophosaurus canadensisMaiasaura peeblesorumShantungosaurus giganteusEdmontosaurus Edmontosaurus regalisEdmontosaurus annectensSaurolophini Kerberosaurus manakiniSabinas OTUProsaurolophus maximusSaurolophus Saurolophus morrisiSaurolophus osborniSaurolophus angustirostrisKritosaurini Wulagasaurus dongiKritosaurus navajovius AquilarhinusSecernosaurus koerneriWillinakaqe salitralensisGryposaurus Gryposaurus latidensGryposaurus notabilisGryposaurus monumentensisPalaeobiology EditMaiasaura lived in herds and it raised its young in nesting colonies The nests in the colonies were packed closely together like those of modern seabirds with the gap between the nests being around 7 metres 23 ft less than the length of the adult animal 12 The nests were made of earth and contained 30 to 40 eggs laid in a circular or spiral pattern The eggs were about the size of ostrich eggs 3 The eggs were incubated by the heat resulting from rotting vegetation placed into the nest by the parents rather than a parent sitting on the nest Upon hatching fossils of baby Maiasaura show that their legs were not fully developed and thus they were incapable of walking Fossils also show that their teeth were partly worn which means that the adults brought food to the nest 3 nbsp Reconstruction of a nest with eggsThe hatchlings grew from a size of 41 to 147 centimetres 16 to 58 in long in the span of their first year At this point or perhaps after another year the animal left the nest This high rate of growth may be evidence of warm bloodedness The hatchlings had different facial proportions from the adults with larger eyes and a shorter snout 3 These features are associated with cuteness and commonly elicit care from parents in animals dependent on their parents for survival during the early stages of life Studies led by Holly Woodward Jack Horner Freedman Fowler et al have given insight into the life history of Maiasaura resulting in what is perhaps the most detailed life history of any dinosaur known and to which all others can be compared From a sample of fifty individual Maiasaura tibiae it was found that Maiasaurs had a mortality rate of about 89 9 in their first year of life If the animals survived their second year their mortality rate would drop to 12 7 The animals would spend their next six years maturing and growing Sexual maturity was found to occur in their third year while skeletal maturity was attained at eight years of age In their eighth year and beyond the mortality rate for Maiasaura would spike back to around 44 4 The studies that followed also found that Maiasaurs were primarily bipedal as juveniles and switched to a more quadrupedal stance as they aged It was also found that Maiasaura also included rotting wood in its diet as well that its environment had a long dry season prone to drought The results of the study were published in the journal Palaeobiology on September 3 2015 13 14 Diet Edit A paper from 2007 showed that Maiasaura had a diet consisting of fibrous plants wood rotting wood tree bark leaves branches ferns angiosperms and possibly grasses This would imply that Maiasaura was both a browser and a grazer 15 16 Sexual dimorphism Edit Studies of Maiasaura by Saitta et al suggest that one sex was roughly 45 larger than the other according to the mathematical analysis known as size statistics However it cannot be ascertained at this time whether the larger gender was male or female 17 18 Palaeoecology Edit nbsp Illustration of a herd of Maiasaura walking along a creekbed as found in the semi arid Two Medicine Formation fossil bed This region was characterized by volcanic ash layers and conifer fern and horsetail vegetation Maiasaura is a characteristic fossil of the middle portion lithofacies 4 of the Two Medicine Formation dated to about 76 4 million years ago 2 Maiasaura lived alongside the troodontid Stenonychosaurus formerly Troodon and the basal ornithopod Orodromeus as well as the dromaeosaurid Bambiraptor and the tyrannosaur Daspletosaurus 2 Another species of hadrosaurids referable to the genus Hypacrosaurus coexisted with Maiasaura for some time as Hypacrosaurus remains have been found lower in the Two Medicine Formation than was earlier known 19 The discovery of an additional hadrosaurid Gryposaurus latidens in the same range as Maiasaura has shown that the border between hypothesized distinct faunas in the upper and middle is less distinct than once thought 19 There seems to be a major diversification in ornithischian taxa after the appearance of Maiasaura within the Two Medicine Formation 19 The thorough examination of strata found along the Two Medicine River which exposes the entire upper half of the Two Medicine Formation indicates that the apparent diversification was a real event rather than a result of preservational biases 19 While Maiasaura has historically been associated with the Two Medicine formation ceratopsid Einiosaurus in a single fauna this is inaccurate as Maiasaura is known exclusively from older strata 20 In the Oldman Formation of Alberta Maiasaura lived alongside the ceratopsians Albertaceratops Anchiceratops Chasmosaurus Coronosaurus and Wendiceratops as well as the dromaeosaurids Dromaeosaurus Saurornitholestes and Hesperonychus the tyrannosaurid Daspletosaurus the orodromine thescelosaurid Albertadromeus the pachycephalosaurs Foraminacephale and Hanssuesia the ornithomimid Struthiomimus the other hadrosaurids Brachylophosaurus Corythosaurus and Parasaurolophus and the ankylosaurid Scolosaurus 1 See also Edit nbsp Dinosaurs portalTimeline of hadrosaur researchFootnotes Edit a b McFeeters Bradley D Evans David C Ryan Michael J Maddin Hillary C 2021 03 01 First occurrence of Maiasaura Dinosauria Hadrosauridae from the Upper Cretaceous Oldman Formation of southern Alberta Canada Canadian Journal of Earth Sciences 58 3 286 296 Bibcode 2021CaJES 58 286M doi 10 1139 cjes 2019 0207 ISSN 0008 4077 S2CID 233851376 a b c Horner J R Schmitt J G Jackson F amp Hanna R 2001 Bones and rocks of the Upper Cretaceous Two Medicine Judith River clastic wedge complex Montana In Field trip guidebook Society of Vertebrate Paleontology 61st Annual Meeting Mesozoic and Cenozoic Paleontology in the Western Plains and Rocky Mountains Museum of the Rockies Occasional Paper Vol 3 pp 3 14 a b c d e f Maiasaura Dodson et al 1994 pages 116 117 Wosik M Chiba K Therrien F Evans D C 2020 Testing Size frequency Distributions As a Method of Ontogenetic Aging A Life history Assessment of Hadrosaurid Dinosaurs from the Dinosaur Park Formation of Alberta Canada with Implications for Hadrosaurid Paleoecology Paleobiology 46 3 379 404 doi 10 1017 pab 2020 2 S2CID 221666530 Cubo Jorge Woodward Holly Wolff Ewan Horner John R 2015 First Reported Cases of Biomechanically Adaptive Bone Modeling in Non Avian Dinosaurs PLOS ONE 10 7 e0131131 Bibcode 2015PLoSO 1031131C doi 10 1371 journal pone 0131131 PMC 4495995 PMID 26153689 Judithian Climax Lehman 2001 page 315 Horner J R Makela R 1979 Nest of juveniles provides evidence of family structure among dinosaurs Nature 282 5736 296 298 Bibcode 1979Natur 282 296H doi 10 1038 282296a0 S2CID 4370793 Horner and Gorman 1988 Introduction Trexler 2001 pages 299 300 Faunal Turnover Migration and Evolution Trexler 2001 page 304 Prieto Marquez A Wagner J R 2013 A new species of saurolophine hadrosaurid dinosaur from the Late Cretaceous of the Pacific coast of North America Acta Palaeontologica Polonica 58 2 255 268 doi 10 4202 app 2011 0049 Palmer 1999 page 148 Largest dinosaur population growth study ever shows how Maiasaura lived and died Decades of research on Montana s state fossil the good mother lizard Maiasaura peeblesorum has resulted in the most detailed life history of any dinosaur known Woodward Holly N Freedman Fowler Elizabeth A Farlow James O Horner John R 2015 Maiasaura a model organism for extinct vertebrate population biology A large sample statistical assessment of growth dynamics and survivorship Paleobiology 41 4 503 527 doi 10 1017 pab 2015 19 S2CID 85902880 Chin Karen 1 September 2007 The Paleobiological Implications of Herbivorous Dinosaur Coprolites from the Upper Cretaceous Two Medicine Formation of Montana Why Eat Wood PALAIOS 22 5 554 566 Bibcode 2007Palai 22 554C doi 10 2110 palo 2006 p06 087r JSTOR 27670451 S2CID 86197149 Retrieved 29 August 2020 The Best of all Mothers Maiasaura peeblesorum bioweb uwlax edu University of Wisconsin La Crosse Retrieved 22 March 2021 Using math to examine the sex differences in dinosaurs Statistical analysis reveals differences between dinosaur sexes a b c d Faunal Turnover Migration and Evolution Trexler 2001 page 306 Sullivan R M Lucas S G 2006 The Kirtlandian land vertebrate age faunal composition temporal position and biostratigraphic correlation in the nonmarine Upper Cretaceous of western North America New Mexico Museum of Natural History and Science Bulletin 35 7 29 References Edit nbsp Wikimedia Commons has media related to Maiasaura Dodson Peter amp Britt Brooks amp Carpenter Kenneth amp Forster Catherine A amp Gillette David D amp Norell Mark A amp Olshevsky George amp Parrish J Michael amp Weishampel David B The Age of Dinosaurs Publications International LTD p 116 117 ISBN 0 7853 0443 6 Horner Jack and Gorman James 1988 Digging Dinosaurs The Search that Unraveled the Mystery of Baby Dinosaurs Workman Publishing Co Lehman T M 2001 Late Cretaceous dinosaur provinciality In Mesozoic Vertebrate Life edited by Tanke D H and Carpenter K Indiana University Press pp 310 328 Palmer D ed 1999 The Marshall Illustrated Encyclopedia of Dinosaurs and Prehistoric Animals London Marshall Editions p 148 ISBN 1 84028 152 9 Trexler D 2001 Two Medicine Formation Montana geology and fauna In Mesozoic Vertebrate Life edited by Tanke D H and Carpenter K Indiana University Press pp 298 309 Retrieved from https en wikipedia org w index php title Maiasaura amp oldid 1162457040, wikipedia, wiki, book, books, library,

article

, read, download, free, free download, mp3, video, mp4, 3gp, jpg, jpeg, gif, png, picture, music, song, movie, book, game, games.