803:
114:
123:
678:
155:
918:
782:
645:
720:
741:
924:
866:
However, this traditional tree was only weakly supported and not statistically significantly different from the alternative
Ornithoscelida hypothesis. With only minor adjustments made by Baron and colleagues in response, Ornithoscelida was found to be preferred over the traditional model once more.
865:
The
Ornithoscelida hypothesis has been challenged by a team of international researchers in November 2017, following a reworking of the original anatomical dataset from Baron et al. (2017). This reworking produced the traditional model, with Ornithischia and Saurischia recovered as sister-taxa.
584:
dinosaurs belong. Previous analyses had rather combined the
Theropoda with the Sauropodomorpha into the Saurischia, to the exclusion of the Ornithischia. These groups had also been formally defined to reflect this. Using these standard definitions, the new results would have had the effect of
522:
Ornithoscelida are "bird hipped" clade. The hip bone is made out of 3 parts: The Ilion, The Pubis, and the
Isquion. The Ornithoscelida's Pubis and Isquion bone are together while in the lizard hipped bone they are separate. The Ornithoscelida clade includes dinosaurs like the triceratops,
531:. A way to distinguish these dinosaurs apart from others is their jaw. Ornithoscelida feature an extra bone found at the end of their lower jaw. Most ornithischians also had interlacing of boney tendons intertwined with their adjacent projections in the vertebrae column.
585:
bringing the
Ornithischia within the Saurischia and indeed the Theropoda; and the Sauropodomorpha outside the Dinosauria. To avoid this, Baron and colleagues redefined all these groups. Proposing that the Ornithischia and Theropoda were
372:
length, and the latter with longer cervical vertebrae, and the femur length shorter than tibia length. He noted that the characteristics of their bones showed many features akin to birds. The dinosaurs Huxley had divided into three
853:
A follow-up study, presented by Parry, Baron and
Vinther (2017), demonstrated how, if using the same dataset, the Ornithoscelida hypothesis can also be recovered using a range of different phylogenetic analysis methods, including
802:
589:
also meant that a new name was needed for the clade combining them. For this clade, they brought back the name
Ornithoscelida, defining it as "the least inclusive clade that includes
1198:
Max C. Langer; Martín D. Ezcurra; Oliver W. M. Rauhut; Michael J. Benton; Fabien Knoll; Blair W. McPhee; Fernando E. Novas; Diego Pol; Stephen L. Brusatte (2017).
499:
in
Dinosauria and divided dinosaurs into Sauropoda and Ornithoscelida, the latter including taxa that would later be considered theropods and ornithischians.
613:; and all its descendants. Huxley's old name Ornithoscelida was chosen because its meaning, "bird legs", well fitted the hindlimb traits of the clade. The
858:
maximum-likelihood. The same study, when analysing a modified version of the original Baron et al. (2017) dataset, also found some support for the
350:
originally defined the term in an 1869 lecture as a group comprising two subgroups: the large and heavy-set
Dinosauria and the newly discovered
1331:
1199:
113:
154:
1084:
554:
vastly increased the available information on the origins of the
Ornithischia. In March 2017, a paper in the journal
1326:
1038:
954:
Carrano, M.; Benson, R.; Sampson, Scott D. (2012). "The phylogeny of Tetanurae (Dinosauria: Theropoda)".
1273:
1234:
1214:
1154:
1099:
1002:
855:
602:
597:
132:
347:
320:
316:
217:
1321:
1297:
1246:
1123:
971:
361:
149:
901:
677:
1289:
1238:
1180:
1115:
1020:
591:
544:
122:
1281:
1230:
1222:
1170:
1162:
1107:
1010:
963:
932:
555:
428:
374:
257:
875:
859:
736:
715:
624:
577:
569:
561:
502:
This classification quickly fell out of use, due to the dominant classification system by
423:
357:
925:
On the Classification of the Dinosauria, with observations on the Dinosauria of the Trias
1277:
1218:
1158:
1103:
1006:
1175:
1142:
458:
404:
381:
936:
1315:
1301:
1250:
1127:
550:
475:
452:
434:
416:
352:
137:
71:
29:
975:
781:
776:
673:
586:
573:
540:
511:
503:
440:
410:
398:
392:
386:
328:
236:
1059:
644:
1264:
Matthew G. Baron; David B. Norman; Paul M. Barrett (2017). "Baron et al. reply".
967:
539:
In the beginning of the twenty-first century, improved descriptions of the early
719:
524:
481:
463:
446:
46:
940:
917:
880:
740:
701:
690:
639:
528:
507:
487:
332:
324:
91:
56:
798:
614:
469:
241:
166:
96:
40:
1293:
1242:
1184:
1119:
1024:
1085:"A new hypothesis of dinosaur relationships and early dinosaur evolution"
581:
565:
312:
199:
186:
86:
81:
66:
61:
51:
33:
1285:
1226:
1166:
1111:
903:
The Century Dictionary: An Encyclopedic Lexicon of the English Language
101:
76:
176:
1015:
990:
369:
365:
308:
1060:"Ornithischian | Triassic, Jurassic, Cretaceous | Britannica"
263:
1039:"Bird-Hipped and Lizard-Hipped Dinosaurs – Creation Moments"
275:
1083:
Baron, Matthew G.; Norman, David B.; Barrett, Paul (2017).
299:
287:
278:
601:." This means that this node-based clade consists of the
293:
272:
1141:
Luke A. Parry; Matthew G. Baron; Jakob Vinther (2017).
564:, and Paul Barrett, published an analysis in which the
906:, vol. V, New York: The Century Co., p. 4158
1143:"Multiple optimality criteria support Ornithoscelida"
929:
Quarterly Journal of the Geological Society of London
315:. An order Ornithoscelida was originally proposed by
284:
269:
260:
296:
290:
266:
233:
281:
617:below shows the phylogeny from Baron et al. 2017:
862:hypothesis when using certain types of analysis.
506:that grouped dinosaurs into two main branches:
8:
360:. The former were defined by their shorter
331:. The term was revived in 2017 after a new
121:
112:
20:
1235:1983/d088dae2-c7fa-4d41-9fa2-aeebbfcd2fa3
1174:
1014:
311:that includes various major groupings of
991:"Palaeontology: Dividing the dinosaurs"
892:
1200:"Untangling the dinosaur family tree"
568:dinosaurs — no longer containing the
7:
356:, which he placed in a new grouping
956:Journal of Systematic Palaeontology
768:
707:
696:
665:
630:
620:
136:mounted skeleton (top) and a male
14:
937:10.1144/gsl.jgs.1870.026.01-02.09
931:. Vol. 26. pp. 32–51.
916:
900:Whitney, William Dwight (1897),
801:
780:
739:
718:
676:
643:
319:but later abandoned in favor of
256:
153:
572:— were more closely related to
323:'s division of Dinosauria into
1:
1332:Fossil taxa described in 2017
495:S. Williston (1878) included
968:10.1080/14772019.2011.630927
923:Huxley, Thomas H. (1870). "
1348:
1147:Royal Society Open Science
796:
773:
766:
733:
712:
705:
694:
670:
663:
635:
628:
580:, the group to which the
230:
225:
150:Scientific classification
148:
129:
120:
111:
23:
605:of the extant theropod
342:
989:Padian, Kevin (2017).
609:and the ornithischian
576:dinosaurs than to the
603:last common ancestor
598:Triceratops horridus
133:Triceratops horridus
1286:10.1038/nature24012
1278:2017Natur.551E...4B
1227:10.1038/nature24011
1219:2017Natur.551E...1L
1167:10.1098/rsos.170833
1159:2017RSOS....470833P
1112:10.1038/nature21700
1104:2017Natur.543..501B
1007:2017Natur.543..494P
504:Harry Govier Seeley
450:(tentatively), and
348:Thomas Henry Huxley
321:Harry Govier Seeley
317:Thomas Henry Huxley
1064:www.britannica.com
560:by Matthew Baron,
362:cervical vertebrae
335:analysis by Baron
1327:Dinosaur taxonomy
1098:(7646): 501–506.
1001:(7646): 494–495.
850:
849:
841:
840:
832:
831:
823:
822:
814:
813:
752:
751:
592:Passer domesticus
545:Heterodontosaurus
368:length exceeding
249:
248:
221:
142:Passer domesticus
16:Clade of reptiles
1339:
1306:
1305:
1261:
1255:
1254:
1204:
1195:
1189:
1188:
1178:
1138:
1132:
1131:
1089:
1080:
1074:
1073:
1071:
1070:
1056:
1050:
1049:
1047:
1046:
1035:
1029:
1028:
1018:
986:
980:
979:
951:
945:
944:
920:
914:
908:
907:
897:
805:
785:
784:
769:
743:
722:
708:
697:
680:
666:
660:
647:
631:
621:
429:Thecodontosaurus
343:Huxley's concept
307:) is a proposed
306:
305:
302:
301:
298:
295:
292:
289:
286:
283:
280:
277:
274:
271:
268:
265:
262:
235:
216:
158:
157:
125:
116:
106:
43:
27:Temporal range:
24:Ornithoscelidans
21:
1347:
1346:
1342:
1341:
1340:
1338:
1337:
1336:
1312:
1311:
1310:
1309:
1272:(7678): E4–E5.
1263:
1262:
1258:
1213:(7678): E1–E3.
1202:
1197:
1196:
1192:
1140:
1139:
1135:
1087:
1082:
1081:
1077:
1068:
1066:
1058:
1057:
1053:
1044:
1042:
1037:
1036:
1032:
1016:10.1038/543494a
988:
987:
983:
953:
952:
948:
922:
915:
911:
899:
898:
894:
889:
876:Phytodinosauria
872:
860:Phytodinosauria
851:
842:
833:
824:
815:
779:
753:
737:Sauropodomorpha
716:Herrerasauridae
661:
658:
625:Dinosauromorpha
578:Sauropodomorpha
570:Herrerasauridae
537:
520:
424:Scelidosauridae
345:
259:
255:
215:
152:
107:
105:
104:
99:
94:
89:
84:
79:
74:
69:
64:
59:
54:
49:
38:
37:
28:
25:
17:
12:
11:
5:
1345:
1343:
1335:
1334:
1329:
1324:
1314:
1313:
1308:
1307:
1256:
1190:
1153:(10): 170833.
1133:
1075:
1051:
1030:
981:
962:(2): 211–300.
946:
909:
891:
890:
888:
885:
884:
883:
878:
871:
868:
848:
847:
844:
843:
839:
838:
835:
834:
830:
829:
826:
825:
821:
820:
817:
816:
812:
811:
808:
807:
795:
792:
791:
788:
787:
772:
767:
765:
763:Ornithoscelida
759:
758:
755:
754:
750:
749:
746:
745:
732:
729:
728:
725:
724:
711:
706:
704:
695:
693:
687:
686:
683:
682:
669:
664:
662:
657:
654:
653:
650:
649:
634:
629:
627:
619:
541:ornithischians
536:
533:
519:
516:
493:
492:
459:Iguanodontidae
456:
421:
405:Poekilopleuron
382:Megalosauridae
344:
341:
252:Ornithoscelida
247:
246:
245:
244:
239:
228:
227:
223:
222:
213:Ornithoscelida
210:
203:
202:
197:
190:
189:
184:
180:
179:
174:
170:
169:
164:
160:
159:
146:
145:
127:
126:
118:
117:
109:
108:
100:
95:
90:
85:
80:
75:
70:
65:
60:
55:
50:
45:
44:
26:
15:
13:
10:
9:
6:
4:
3:
2:
1344:
1333:
1330:
1328:
1325:
1323:
1320:
1319:
1317:
1303:
1299:
1295:
1291:
1287:
1283:
1279:
1275:
1271:
1267:
1260:
1257:
1252:
1248:
1244:
1240:
1236:
1232:
1228:
1224:
1220:
1216:
1212:
1208:
1201:
1194:
1191:
1186:
1182:
1177:
1172:
1168:
1164:
1160:
1156:
1152:
1148:
1144:
1137:
1134:
1129:
1125:
1121:
1117:
1113:
1109:
1105:
1101:
1097:
1093:
1086:
1079:
1076:
1065:
1061:
1055:
1052:
1040:
1034:
1031:
1026:
1022:
1017:
1012:
1008:
1004:
1000:
996:
992:
985:
982:
977:
973:
969:
965:
961:
957:
950:
947:
942:
938:
934:
930:
926:
919:
913:
910:
905:
904:
896:
893:
886:
882:
879:
877:
874:
873:
869:
867:
863:
861:
857:
846:
845:
837:
836:
828:
827:
819:
818:
810:
809:
806:
804:
800:
794:
793:
790:
789:
786:
783:
778:
771:
770:
764:
761:
760:
757:
756:
748:
747:
744:
742:
738:
731:
730:
727:
726:
723:
721:
717:
710:
709:
703:
699:
698:
692:
689:
688:
685:
684:
681:
679:
675:
668:
667:
656:
655:
652:
651:
648:
646:
642:
641:
633:
632:
626:
623:
622:
618:
616:
612:
608:
604:
600:
599:
594:
593:
588:
587:sister groups
583:
579:
575:
574:ornithischian
571:
567:
563:
559:
558:
553:
552:
551:Lesothosaurus
547:
546:
542:
535:Modern theory
534:
532:
530:
526:
525:Stegosauruses
517:
515:
513:
509:
505:
500:
498:
497:Compsognathus
491:(tentatively)
490:
489:
484:
483:
478:
477:
476:Hypsilophodon
472:
471:
466:
465:
460:
457:
455:
454:
453:Acanthopholis
449:
448:
443:
442:
437:
436:
435:Scelidosaurus
431:
430:
425:
422:
420:(tentatively)
419:
418:
417:Euskelosaurus
413:
412:
407:
406:
401:
400:
395:
394:
389:
388:
383:
380:
379:
378:
376:
371:
367:
363:
359:
355:
354:
353:Compsognathus
349:
340:
338:
334:
330:
326:
322:
318:
314:
310:
304:
253:
243:
240:
238:
232:
231:
229:
224:
219:
214:
211:
208:
205:
204:
201:
198:
195:
192:
191:
188:
185:
182:
181:
178:
175:
172:
171:
168:
165:
162:
161:
156:
151:
147:
143:
139:
138:house sparrow
135:
134:
128:
124:
119:
115:
110:
103:
98:
93:
88:
83:
78:
73:
68:
63:
58:
53:
48:
42:
39:231.4–0
35:
31:
30:Late Triassic
22:
19:
1269:
1265:
1259:
1210:
1206:
1193:
1150:
1146:
1136:
1095:
1091:
1078:
1067:. Retrieved
1063:
1054:
1043:. Retrieved
1041:. 2018-11-22
1033:
998:
994:
984:
959:
955:
949:
939:– via
928:
912:
902:
895:
864:
852:
797:
777:Ornithischia
774:
762:
734:
713:
674:Silesauridae
671:
638:
636:
610:
606:
596:
590:
562:David Norman
556:
549:
543:
538:
529:Ceratopsians
521:
512:Ornithischia
501:
496:
494:
486:
480:
474:
468:
462:
451:
445:
441:Hylaeosaurus
439:
433:
427:
415:
409:
403:
399:Megalosaurus
397:
393:Palaeosaurus
391:
387:Teratosaurus
385:
358:Compsognatha
351:
346:
336:
329:Ornithischia
251:
250:
237:Ornithischia
212:
206:
193:
141:
131:
18:
611:Triceratops
482:Hadrosaurus
464:Cetiosaurus
447:Polacanthus
144:, bottom).
1316:Categories
1069:2024-07-18
1045:2024-07-18
941:Wikisource
887:References
881:Saurischia
702:Saurischia
691:Dinosauria
640:Marasuchus
508:Saurischia
488:Stenopelix
364:, and the
325:Saurischia
226:Subgroups
200:Dinosauria
1322:Dinosaurs
1302:205260360
1251:205260354
1128:205254710
799:Theropoda
615:cladogram
527:and even
470:Iguanodon
333:cladistic
313:dinosaurs
242:Theropoda
173:Kingdom:
167:Eukaryota
1294:29094705
1243:29094688
1185:29134086
1120:28332513
1025:28332523
976:85354215
870:See also
856:Bayesian
582:sauropod
566:theropod
375:families
187:Chordata
183:Phylum:
177:Animalia
163:Domain:
1274:Bibcode
1215:Bibcode
1176:5666269
1155:Bibcode
1100:Bibcode
1003:Bibcode
659:unnamed
518:Details
411:Laelaps
34:Present
32:–
1300:
1292:
1266:Nature
1249:
1241:
1207:Nature
1183:
1173:
1126:
1118:
1092:Nature
1023:
995:Nature
974:
921:
607:Passer
557:Nature
485:, and
414:, and
220:, 1870
218:Huxley
1298:S2CID
1247:S2CID
1203:(PDF)
1124:S2CID
1088:(PDF)
972:S2CID
370:tibia
366:femur
337:et al
309:clade
207:Clade
194:Clade
1290:PMID
1239:PMID
1181:PMID
1116:PMID
1021:PMID
595:and
548:and
510:and
327:and
47:PreꞒ
1282:doi
1270:551
1231:hdl
1223:doi
1211:551
1171:PMC
1163:doi
1108:doi
1096:543
1011:doi
999:543
964:doi
933:doi
927:".
1318::
1296:.
1288:.
1280:.
1268:.
1245:.
1237:.
1229:.
1221:.
1209:.
1205:.
1179:.
1169:.
1161:.
1149:.
1145:.
1122:.
1114:.
1106:.
1094:.
1090:.
1062:.
1019:.
1009:.
997:.
993:.
970:.
960:10
958:.
514:.
479:,
473:,
467:,
461::
444:,
438:,
432:,
426::
408:,
402:,
396:,
390:,
384::
377::
339:.
264:ɔː
209::
196::
130:A
97:Pg
41:Ma
36:,
1304:.
1284::
1276::
1253:.
1233::
1225::
1217::
1187:.
1165::
1157::
1151:4
1130:.
1110::
1102::
1072:.
1048:.
1027:.
1013::
1005::
978:.
966::
943:.
935::
775:†
735:†
714:†
700:†
672:†
637:†
303:/
300:ə
297:d
294:ɪ
291:l
288:ɛ
285:s
282:ˈ
279:ə
276:θ
273:ɪ
270:n
267:r
261:ˌ
258:/
254:(
234:†
140:(
102:N
92:K
87:J
82:T
77:P
72:C
67:D
62:S
57:O
52:Ꞓ
Text is available under the Creative Commons Attribution-ShareAlike License. Additional terms may apply.
