{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,9,26]],"date-time":"2026-09-26T13:53:11Z","timestamp":1790430791836,"version":"4.1.0"},"reference-count":39,"publisher":"The Company of Biologists","issue":"18","license":[{"start":{"date-parts":[[1998,9,15]],"date-time":"1998-09-15T00:00:00Z","timestamp":905817600000},"content-version":"vor","delay-in-days":0,"URL":"http:\/\/www.biologists.com\/user-licence-1-1\/"}],"content-domain":{"domain":[],"crossmark-restriction":false},"short-container-title":[],"published-print":{"date-parts":[[1998,9,15]]},"abstract":"<jats:title>ABSTRACT<\/jats:title>\n               <jats:p>In terms of locomotory posture, amphibians and lizards are considered to be sprawlers, mammals and dinosaurs are considered to be erect, and extant crocodilians are considered to be intermediate because they use the \u2018high walk\u2019, a semi-erect posture where the body is held half-way between the sprawling and erect grades during locomotion. In addition, crocodilians occasionally use a sprawling posture. Extant crocodilians, therefore, provide an interesting model in which to investigate the sprawling-to-erect transition in vertebrate evolution. This study quantifies the sprawl and high walk kinematics of the alligator Alligator mississippiensis moving at different speeds on a treadmill and compares them with kinematic data available for other vertebrates. These data allow us to examine the effects of speed on crocodilian postures and to examine how crocodilian locomotion relates to the sprawling-to-erect paradigm in vertebrate locomotion.<\/jats:p>\n               <jats:p>Our results show that the crocodilian sprawl is not functionally equivalent to the primitive sprawling behaviors exhibited by salamanders and lizards. In fact, although the high walks and sprawls of alligators exhibit some kinematic differences, they are actually much more similar than expected and, essentially, the crocodilian sprawl is a lower version of a high walk and could be termed a \u2018low walk\u2019.<\/jats:p>\n               <jats:p>In terms of the sprawling-to-erect transition, the high walk has knee kinematics intermediate between those of birds and non-archosaurian tetrapods, but alligators increase speed in a way completely different from other terrestrial vertebrates (distal rather than proximal limb elements are used to increase speed). These kinematic data viewed in the light of the fossil and phylogenetic evidence that modern crocodilians evolved from erect ancestors suggest that modern crocodilians have secondarily evolved a variable semi-erect posture and that they are problematic as an intermediate model for the evolutionary transition from sprawling to erect postures in archosaurs.<\/jats:p>","DOI":"10.1242\/jeb.201.18.2559","type":"journal-article","created":{"date-parts":[[2021,4,23]],"date-time":"2021-04-23T23:27:53Z","timestamp":1619220473000},"page":"2559-2574","source":"Crossref","is-referenced-by-count":132,"title":["Locomotion in <i>Alligator mississippiensis<\/i>: kinematic effects of speed and posture and their relevance to the sprawling-to-erect paradigm"],"prefix":"10.1242","volume":"201","author":[{"given":"Stephen M.","family":"Reilly","sequence":"first","affiliation":[{"name":"Ohio University Department of Biological Sciences , , Athens, OH 45701, USA"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Jason A.","family":"Elias","sequence":"additional","affiliation":[{"name":"Ohio University Department of Biological Sciences , , Athens, OH 45701, USA"}],"role":[{"vocabulary":"crossref","role":"author"}]}],"member":"237","published-online":{"date-parts":[[1998,9,15]]},"reference":[{"key":"2024110710414447300_JEXBIO_201_18_2559C1","doi-asserted-by":"publisher","first-page":"285","DOI":"10.1242\/jeb.193.1.285","article-title":"Metamorphic and speed effects on hindlimb kinematics during terrestrial locomotion in the salamander Dicamptodon tenebrosus.","volume":"193","author":"Ashley-Ross","year":"1994","journal-title":"J. exp. Biol"},{"key":"2024110710414447300_JEXBIO_201_18_2559C2","doi-asserted-by":"publisher","first-page":"255","DOI":"10.1242\/jeb.193.1.255","article-title":"Hindlimb kinematics during terrestrial locomotion in a salamander (Dicamptodon tenebrosus)","volume":"193","author":"Ashley-Ross","year":"1994","journal-title":"J. exp. Biol"},{"key":"2024110710414447300_JEXBIO_201_18_2559C3","doi-asserted-by":"publisher","first-page":"273","DOI":"10.1007\/BF00192417","article-title":"Patterns of hindlimb motor output during walking in the salamander Dicamptodon tenebrosus, with comparisons to other tetrapods","volume":"177","author":"Ashley-Ross","year":"1995","journal-title":"J. comp. Physiol. A"},{"key":"2024110710414447300_JEXBIO_201_18_2559C4","doi-asserted-by":"publisher","first-page":"636","DOI":"10.2307\/2406945","article-title":"Dinosaur physiology and the origin of mammals","volume":"25","author":"Bakker","year":"1971","journal-title":"Evolution"},{"key":"2024110710414447300_JEXBIO_201_18_2559C5","doi-asserted-by":"publisher","first-page":"2187","DOI":"10.1139\/z80-301","article-title":"The hindlimb step cycle of Caiman sclerops and the mechanics of the crocodile tarsus and metatarsus","volume":"58","author":"Brinkman","year":"1980","journal-title":"Can. J. Zool."},{"key":"2024110710414447300_JEXBIO_201_18_2559C6","first-page":"121","article-title":"The evolution of the archosaur pelvis and hindlimb: an explanation in functional terms","volume-title":"Studies in Vertebrate Evolution","author":"Charig","year":"1972"},{"key":"2024110710414447300_JEXBIO_201_18_2559C7","doi-asserted-by":"publisher","first-page":"211","DOI":"10.1111\/j.1096-3642.1961.tb00220.x","article-title":"Scientific results of an inquiry into the ecology and economic status of the Nile crocodile, Crocodylus niloticus, in Uganda and Northern Rhodesia","volume":"29","author":"Cott","year":"1961","journal-title":"Trans. zool. Soc. Lond"},{"key":"2024110710414447300_JEXBIO_201_18_2559C8","first-page":"131","article-title":"A late triassic sphenosuchid crocodilian from Wales","volume":"27","author":"Crush","year":"1984","journal-title":"Palaeontology"},{"key":"2024110710414447300_JEXBIO_201_18_2559C9","doi-asserted-by":"publisher","first-page":"494","DOI":"10.1111\/j.1558-5646.1974.tb00777.x","article-title":"Dinosaurs as dinosaurs","volume":"28","author":"Dodson","year":"1974","journal-title":"Evolution"},{"key":"2024110710414447300_JEXBIO_201_18_2559C10","doi-asserted-by":"crossref","first-page":"553","DOI":"10.1007\/978-1-4684-8851-7_20","article-title":"The evolution of terrestrial locomotion","volume-title":"Major Patterns in Vertebrate Evolution","author":"Edwards","year":"1977"},{"key":"2024110710414447300_JEXBIO_201_18_2559C11","doi-asserted-by":"publisher","first-page":"170","DOI":"10.1017\/S0094837300009866","article-title":"Caudifemoralis musculature and the evolution of theropod locomotion","volume":"16","author":"Gatesy","year":"1990","journal-title":"Paleobiolog"},{"key":"2024110710414447300_JEXBIO_201_18_2559C12","doi-asserted-by":"publisher","first-page":"577","DOI":"10.1111\/j.1469-7998.1991.tb03786.x","article-title":"Hindlimb movements of the American alligator (Alligator mississippiensis) and postural grades","volume":"224","author":"Gatesy","year":"1991","journal-title":"J. Zool., Lond"},{"key":"2024110710414447300_JEXBIO_201_18_2559C13","doi-asserted-by":"publisher","first-page":"1","DOI":"10.1159\/000113619","article-title":"Neuromuscular diversity in archosaur deep dorsal thigh muscles","volume":"43","author":"Gatesy","year":"1994","journal-title":"Brain Behav. Evol"},{"key":"2024110710414447300_JEXBIO_201_18_2559C14","doi-asserted-by":"publisher","first-page":"197","DOI":"10.1002\/(SICI)1097-4687(199711)234:2&lt;197::AID-JMOR6&gt;3.0.CO;2-9","article-title":"An electromyographical analysis of hindlimb function in Alligator during terrestrial locomotion","volume":"234","author":"Gatesy","year":"1997","journal-title":"J. Morph"},{"key":"2024110710414447300_JEXBIO_201_18_2559C15","doi-asserted-by":"publisher","first-page":"280","DOI":"10.1080\/02724634.1997.10010975","article-title":"A crocodyliform from the early cretaceous dinosaur beds, northern Malawi","volume":"17","author":"Gomani","year":"1997","journal-title":"J. Vert. Paleont"},{"key":"2024110710414447300_JEXBIO_201_18_2559C16","doi-asserted-by":"publisher","first-page":"1","DOI":"10.1002\/jmor.1051410102","article-title":"The cat step cycle: hindlimb joint angles and muscle lengths during unrestrained locomotion","volume":"141","author":"Goslow","year":"1973","journal-title":"J. Morph"},{"key":"2024110710414447300_JEXBIO_201_18_2559C17","doi-asserted-by":"publisher","first-page":"15","DOI":"10.1242\/jeb.94.1.15","article-title":"Electrical activity and relative length changes of dog limb muscles as a function of speed and gait","volume":"94","author":"Goslow","year":"1981","journal-title":"J. exp. Biol"},{"key":"2024110710414447300_JEXBIO_201_18_2559C18","doi-asserted-by":"publisher","first-page":"267","DOI":"10.1111\/j.1749-6632.1912.tb55164.x","article-title":"Notes on the principles of quadrupedal locomotion and on the mechanism of the limbs in hoofed animals","volume":"22","author":"Gregory","year":"1912","journal-title":"Ann. N.Y. Acad. Sci"},{"key":"2024110710414447300_JEXBIO_201_18_2559C19","doi-asserted-by":"publisher","first-page":"247","DOI":"10.1152\/physrev.1975.55.2.247","article-title":"Locomotion in vertebrates: central mechanisms and reflex action","volume":"55","author":"Grillner","year":"1975","journal-title":"Physiol. Rev"},{"key":"2024110710414447300_JEXBIO_201_18_2559C20","first-page":"1179","article-title":"Control of locomotion in bipeds, tetrapods and fish","volume-title":"Handbook of Physiology","author":"Grillner","year":"1981"},{"key":"2024110710414447300_JEXBIO_201_18_2559C21","first-page":"1","article-title":"The stride cycle of the cat: the modeling of locomotion by computerized analysis of automatic recordings","volume":"521","author":"Halbertsma","year":"1983","journal-title":"Acta physiol. scand"},{"key":"2024110710414447300_JEXBIO_201_18_2559C22","doi-asserted-by":"crossref","first-page":"38","DOI":"10.4159\/harvard.9780674184404.c3","article-title":"Walking and running","volume-title":"Functional Vertebrate Morphology","author":"Hildebrand","year":"1985"},{"key":"2024110710414447300_JEXBIO_201_18_2559C23","doi-asserted-by":"publisher","first-page":"303","DOI":"10.1111\/j.1469-7998.1971.tb02189.x","article-title":"Limb posture and locomotion in the Virginia opossum (Didelphus marsupialis) and in other noncursorial mammals","volume":"165","author":"Jenkins","year":"1971","journal-title":"J. Zool., Lond"},{"key":"2024110710414447300_JEXBIO_201_18_2559C24","volume-title":"Vertebrates: Comparative Anatomy, Function, Evolution.","author":"Kardong","year":"1995"},{"key":"2024110710414447300_JEXBIO_201_18_2559C25","doi-asserted-by":"publisher","first-page":"589","DOI":"10.1113\/jphysiol.1996.sp021406","article-title":"Ontogeny of bipedal locomotion: walking and running in the chick","volume":"493","author":"Muir","year":"1990","journal-title":"J. Physiol., Lond."},{"key":"2024110710414447300_JEXBIO_201_18_2559C26","first-page":"1","article-title":"Locomotor adaptations in the hindlimb and pelvis of the thecodontia","volume":"1","author":"Parrish","year":"1986","journal-title":"Hunteria"},{"key":"2024110710414447300_JEXBIO_201_18_2559C27","doi-asserted-by":"publisher","first-page":"396","DOI":"10.1017\/S0094837300009003","article-title":"The origin of crocodilian locomotion","volume":"13","author":"Parrish","year":"1987","journal-title":"Paleobiology"},{"key":"2024110710414447300_JEXBIO_201_18_2559C28","doi-asserted-by":"publisher","first-page":"53","DOI":"10.1111\/j.1469-7998.1985.tb05613.x","article-title":"Terrestrial locomotion in monotremes (Mammalia: Monotremata)","volume":"205A","author":"Pridmore","year":"1985","journal-title":"J. Zool., Lond"},{"key":"2024110710414447300_JEXBIO_201_18_2559C29","first-page":"263","article-title":"Quantitative electromyography and muscle function of the hindlimb during locomotion in the lizard Sceloporus clarki","volume":"98","author":"Reilly","year":"1995","journal-title":"Zoology: Anal. compl. Syst."},{"key":"2024110710414447300_JEXBIO_201_18_2559C30","doi-asserted-by":"publisher","first-page":"417","DOI":"10.1111\/j.1469-7998.1997.tb02791.x","article-title":"Sprawling locomotion in the lizard Sceloporus clarki: the effects of speed on gait, hindlimb kinematics and axial bending during walking","volume":"243","author":"Reilly","year":"1997","journal-title":"J. Zool., Lond"},{"key":"2024110710414447300_JEXBIO_201_18_2559C31","doi-asserted-by":"publisher","first-page":"753","DOI":"10.1242\/jeb.200.4.753","article-title":"Sprawling locomotion in the lizard Sceloporus clarki: quantitative kinematics of a walking trot","volume":"200","author":"Reilly","year":"1997","journal-title":"J. exp. Biol"},{"key":"2024110710414447300_JEXBIO_201_18_2559C32","doi-asserted-by":"publisher","first-page":"147","DOI":"10.1111\/j.1469-7998.1980.tb01454.x","article-title":"Form and function in lacertilian knee and mesotarsal joints: a contribution to the analysis of sprawling locomotion","volume":"191","author":"Rewcastle","year":"1980","journal-title":"J. Zool., Lond"},{"key":"2024110710414447300_JEXBIO_201_18_2559C33","first-page":"239","article-title":"Stance and gait in tetrapods: an evolutionary scenario","volume":"48","author":"Rewcastle","year":"1981","journal-title":"Symp. zool. Soc. Lond"},{"key":"2024110710414447300_JEXBIO_201_18_2559C34","first-page":"63","article-title":"Basic evolutionary laws of development of the locomotor apparatus in the archosaurs","volume":"4","author":"Sennikov","year":"1989","journal-title":"Paleont. Zhur"},{"key":"2024110710414447300_JEXBIO_201_18_2559C35","doi-asserted-by":"publisher","first-page":"308","DOI":"10.1007\/BF00230301","article-title":"Gait-related motor patterns and hindlimb kinematics for the cat trot and gallop","volume":"94","author":"Smith","year":"1993","journal-title":"Exp. Brain Res"},{"key":"2024110710414447300_JEXBIO_201_18_2559C36","volume-title":"Measurement TV: Video Analysis Software.","author":"Updegraff","year":"1990"},{"key":"2024110710414447300_JEXBIO_201_18_2559C37","doi-asserted-by":"publisher","first-page":"441","DOI":"10.1002\/ajpa.1330810313","article-title":"Effects of growth and speed on hindlimb joint angular displacement patterns in vervet monkeys (Cercopithecus aethiops)","volume":"81","author":"Vilensky","year":"1990","journal-title":"Am. J. phys. Anthropol"},{"key":"2024110710414447300_JEXBIO_201_18_2559C38","doi-asserted-by":"publisher","first-page":"607","DOI":"10.3853\/j.0067-1975.34.1982.244","article-title":"Galloping in Crocodylus johnstoni \u2013 a reflection of terrestrial activity?","volume":"34","author":"Webb","year":"1982","journal-title":"Rec. Austral. Mus"},{"key":"2024110710414447300_JEXBIO_201_18_2559C39","volume-title":"Biostatistics: Experimental Design and Statistical Inference","author":"Zolman","year":"1993"}],"container-title":["Journal of Experimental Biology"],"original-title":[],"language":"en","link":[{"URL":"https:\/\/journals.biologists.com\/jeb\/article-pdf\/201\/18\/2559\/3576080\/jexbio_201_18_2559.pdf","content-type":"application\/pdf","content-version":"vor","intended-application":"syndication"},{"URL":"https:\/\/journals.biologists.com\/jeb\/article-pdf\/201\/18\/2559\/3576080\/jexbio_201_18_2559.pdf","content-type":"unspecified","content-version":"vor","intended-application":"similarity-checking"}],"deposited":{"date-parts":[[2024,11,7]],"date-time":"2024-11-07T10:42:00Z","timestamp":1730976120000},"score":1,"resource":{"primary":{"URL":"https:\/\/journals.biologists.com\/jeb\/article\/201\/18\/2559\/7758\/Locomotion-in-Alligator-mississippiensis-kinematic"}},"subtitle":[],"short-title":[],"issued":{"date-parts":[[1998,9,15]]},"references-count":39,"journal-issue":{"issue":"18","published-print":{"date-parts":[[1998,9,15]]}},"URL":"https:\/\/doi.org\/10.1242\/jeb.201.18.2559","relation":{},"ISSN":["0022-0949","1477-9145"],"issn-type":[{"value":"0022-0949","type":"print"},{"value":"1477-9145","type":"electronic"}],"subject":[],"published":{"date-parts":[[1998,9,15]]}}}