728:) "tooth") in 1878, based on part of a lower jaw (dentary) bone found in the redbeds of northern New Mexico by fossil collector David Baldwin. In his very short description of the jaw, Marsh cited the back teeth as characteristic ("crowns are much compressed, and have very sharp cutting edges without crenulations") and assessed the animal as "about six feet in length, and carnivorous in habit," although the rest of the skeleton was not known. He did not provide an illustration of the specimen. Marsh gave the genus the Latin specific name
3324:
1222:
3022:
148:
519:. It is narrow from side to side and vertically deep, with an indented notch at the front of the maxillary bone in the upper jaw. The upper and lower jaws are equipped with an array of powerful teeth, divided into sharp pointed "incisors" , large stabbing "canines" , and smaller slicing back teeth . The orbit is set high and far back with a single opening (temporal fenestra) behind and partly below the eye, a characteristic of synapsids.
3034:
3357:
3028:
593:
2501:
500:
123:
2506:
685:
604:
651:
foot") that match the foot configuration of large sphenacodontids show animals walking with their limbs brought under the body for a narrow, semi-erect gait without tail or belly drag marks. Such clear evidence for a more efficient upright posture suggests that important details about the anatomy and
563:
confirms that the upper parts were not encased in a thick muscular hump and instead protruded above a layer of muscle to form a low dorsal crest. Finds of sphenacodontid specimens in which postmortem distortion of the body caused the dorsal spines to overlap suggests that the spines were not
428:
has helped clarify other distinctions between the two species, including the number of teeth in certain parts of the jaws and the size of the indented notch between the maxillary and premaxillary bones in the upper jaw. The two species occur together in some formations, but
526:, with a very large head, short neck, robust trunk, relatively short front and hind limbs, and a tapering tail that makes up about half the animal's entire length. However, the tops of the neural spines along the back bone are strikingly different in each genus. In
634:
have been depicted with their short limbs splayed outward at 90 degrees from the body in a wide pushup position and with the tail (and even belly) dragging on the ground, similar to modern lizards and crocodiles. A sprawling stance is also typical for
1623:
559:, likely helping to stiffen and strengthen the backbone for walking and for lunging at prey by restricting side-to-side flexing motion. A recent study of the structure of the neural spines on
817:
Baur, 1906) and so is invalid.) The specimen had been identified earlier as a possible
Triassic dinosaur, but von Huene recognized a "pelycosaur." Paton transferred the species to
534:, the neural spines are enlarged but retain a flat-tipped, blade-like shape along the back and tail, and form a crest rather than a tall sail. (The sphenacodontid genus
3450:
3554:
3514:
1274:
Spielmann, J. A.; Rinehart, Larry F.; Lucas, Spencer G.; Berman, David S.; Henrici, Amy C.; Harris, Susan K. (2010). "Redescription of the cranial anatomy of
3544:
3534:
1624:"Redescription of the Cranial Anatomy of Sphenacodon Ferox Marsh (Eupelycosauria: Sphenacodontidae) From the Late Pennsylvanian-Early Permian of New Mexico"
530:, the neural spines develop into long, narrow, cylindrical projections that support a tall vertical dorsal sail that ends near the base of the tail. In
790:("fiercer") that was larger and more robust, with proportionately longer neural spines. Romer and Price (1940) provided detailed descriptions of both
3437:
1452:
Huttenlocker, A. K.; Rega, E.; Sumida, S. S. (2010). "Comparative anatomy and osteohistology of hyperelongate neural spines in the sphenacodontids
665:
3549:
3539:
3559:
3524:
3509:
1544:
Hunt, A. P.; Lucas, S. G. (1998). "Vertebrate tracks and the myth of the belly-dragging, tail-dragging tetrapods of the Late
Paleozoic".
1766:
373:
had a low crest along its back, formed from blade-like bones on its vertebrae (neural spines) instead of the tall dorsal sail found in
443:
typically have been found in different geographical areas that were separated by the ancient Hueco Seaway that penetrated equatorial
1401:
3519:
3323:
135:
3529:
467:
is found in New Mexico. Each genus would have been an apex land predator in its region and likely preyed on amphibians,
825:. However, more recent studies have questioned whether such limited fossil material can be used to distinguish between
1068:
934:
3033:
3021:
147:
732:"fierce" and erected the new family Sphenacodontidae, placed under the primitive reptilian order "Rhynchocephala" (=
1044:
3504:
1845:
1622:
Spielmann, Justin A.; Rinehart, Larry F.; Lucas, Spencer G.; Berman, David S.; Harris, Susan K (January 2010).
1872:
1759:
951:
30:
3377:
3225:
3027:
2500:
1339:(Amniota: Synapsida: Sphenacodontidae) from the Lower Permian Abo Formation, Socorro County, New Mexico".
3476:
3132:
3106:
910:
783:
693:
238:
483:
survived until about 270 million years ago. Such large sphenacodontid predators were later replaced by
1505:"Comparative osteohistology of hyperelongate neural spines in the Edaphosauridae (Amniota: Synapsida)"
1316:(Reptilia, Pelycosauria) from a Non-Deltaic Facies in the Lower Permian of North-Central New Mexico".
564:
connected by hard or particularly tough tissue. The possible function of a low, skin-covered crest in
3424:
3190:
3158:
1516:
2505:
1380:
1341:
New Mexico
Geological Society Guidebook, 60th Field Conference, Geology of the Chupadera Mesa Region
3248:
1375:
1278:
Marsh (Eupelycosauria, Sphenacodontidae) from the Late
Pennsylvanian-Early Permian of New Mexico".
1235:
1227:
968:
805:, has sometimes been cited in the literature. In 1908 German paleontologist F. von Huene described
767:
came in the early 20th century with the discovery of more fossils in New Mexico. The proposed taxa
752:
3360:
2907:
2766:
2719:
1752:
1714:"A new basal sphenacodontid synapsid from the Late Carboniferous of the Saar-Nahe Basin, Germany"
1485:
992:
297:
142:
1713:
551:
There is evidence for strong epaxial muscles along the base of the raised neural spines in both
3481:
3463:
3455:
2847:
2820:
1477:
1397:
1370:
1005:
3415:
2877:
2616:
2476:
2119:
1728:
1712:
Jörg Fröbisch; Rainer R. Schoch; Johannes Müller; Thomas
Schindler; Dieter Schweiss (2011).
1524:
1469:
1431:
1030:
447:
during the Early
Permian and "covered much of southern New Mexico and parts of West Texas".
366:
218:
205:
3468:
2943:
2786:
2726:
2586:
2542:
1830:
733:
1520:
3271:
3202:
2900:
2829:
2749:
2712:
2670:
2661:
2413:
2317:
2262:
2251:
2208:
2174:
2084:
1959:
1857:
1109:
896:
884:
755:, became a scientifically important genus, known from numerous fossils. Recognition of
536:
362:
3498:
3345:
3214:
2973:
2965:
2886:
2836:
2806:
2796:
2733:
2593:
2551:
2348:
2333:
2306:
2285:
2147:
2140:
2056:
1529:
1504:
672:, a genus known from skeletal fossils in the state, but could also come from a small
394:
344:
80:
1489:
3350:
3340:
3304:
3164:
3121:
3095:
2957:
2893:
2698:
2684:
2677:
2600:
2572:
2299:
2215:
2154:
2098:
2091:
2049:
2042:
2035:
1984:
1637:
1241:
760:
499:
412:
can be up to 40% larger in overall size (at about 3 m long) compared to
122:
1587:
568:
is debated. A thermoregulatory role seems unlikely, although the taller crest in
3409:
3179:
3147:
2929:
2705:
2565:
2558:
2523:
2466:
2456:
2384:
2292:
2187:
2015:
1993:
1974:
736:), then including nearly all groups of early reptiles in addition to the living
592:
55:
3400:
3294:
3284:
3237:
3064:
3051:
2985:
2915:
2863:
2647:
2579:
2426:
2341:
2326:
2236:
2229:
2201:
2126:
2112:
1217:
1126:
1018:
484:
382:
353:
343:
that lived from about 300 to about 280 million years ago (Ma) during the Late
100:
65:
34:
3081:
2936:
2637:
2362:
2222:
2133:
2077:
2070:
2008:
1938:
1925:
1884:
1775:
1670:
Paton, R. L. (1974). "Lower
Permian pelycosaurs from the English midlands".
860:
468:
192:
159:
105:
49:
42:
1481:
1733:
1651:
Huene, F.v. (1908). "Neue und verkannte
Pelycosaurier: Reste aus Europe".
1394:
The
Marshall Illustrated Encyclopedia of Dinosaurs and Prehistoric Animals
684:
540:
also has blade-like neural spines, but its dorsal crest is taller than in
3394:
2922:
2776:
2691:
2446:
2436:
2369:
2355:
2278:
2271:
2026:
2001:
1805:
1799:
1693:, and comparisons with other sphenacodontines (Reptilia: Pelycosauria)".
1603:
Romer, A. S. (1937). "New genera and species of pelycosaurian reptiles".
1248:
476:
460:
340:
179:
95:
90:
75:
70:
60:
38:
3442:
2105:
1814:
1592:. Washington, D.C.: Carnegie Institution of Washington. pp. 1–176.
1473:
737:
475:
appears to have died out before about 280 million years ago during the
444:
390:
348:
333:
110:
85:
3254:
2244:
1793:
1435:
1299:
Traces of a
Permian Seacoast. Prehistoric Trackways National Monument
643:
skeletons as currently mounted in museums. However, trackways called
488:
169:
3371:
1564:
603:
1335:
Lucas, S.G.; Spielman, J. A.; Rinehart, L.F.; Martens, T. (2009). "
576:. Recent research has favored a display role for the tall sails in
2063:
683:
498:
456:
336:
1381:
https://remodernreview.files.wordpress.com/2015/03/zallinger2.jpg
809:, based on part of a maxilla found in England, (The generic name
3429:
1546:
Bulletin of the New Mexico Museum of Natural History and Science
1280:
Bulletin of the New Mexico Museum of Natural History and Science
386:
3375:
3049:
2521:
1923:
1786:
1748:
1422:
Romer, A.S.; Price, L.I. (1940). "Review of the Pelycosauria".
821:
in 1974, noting it would have been an animal about the size of
775:
Williston and Case, 1913 now are considered junior synonyms of
487:, the group of synapsids that includes the direct ancestors of
718:
710:
702:
451:
is known from the west in New Mexico, Arizona, and Utah, and
416:(at about 2 m ). In addition, the dorsal spines in
1744:
747:
for almost three decades. In the meantime, the sail-backed
1695:
New Mexico Bureau of Mines and Mineral Resources, Circular
743:
Other paleontologists overlooked Marsh's brief mention of
1503:
Huttenlocker, A. K.; Mazierski, D.; Reisz, R. R. (2011).
1653:
Centralblatt für Mineralogie, Geologie und Paläontologie
660:
may not be fully understood. Some well preserved narrow
424:. The recent discovery of a nearly complete skull of
3300:
3290:
3280:
3211:
3176:
3144:
3118:
3092:
3077:
2874:
2859:
2817:
2802:
2792:
2782:
2772:
2762:
2658:
2643:
2633:
2539:
2472:
2462:
2452:
2442:
2432:
2422:
2184:
1971:
1955:
280:
267:
254:
3384:
3269:
3236:
3210:
3201:
3175:
3143:
3117:
3091:
3062:
2984:
2873:
2846:
2816:
2747:
2657:
2614:
2538:
2411:
2383:
2316:
2261:
2183:
2172:
2025:
1983:
1970:
1936:
1883:
1856:
1829:
463:in more deltaic environments. However, the species
849:) is now generally classified as Sphenacodontidae
433:apparently survived later into the Early Permian.
786:described a second species from New Mexico named
1426:. Geological Society of America Special Papers.
1605:Proceedings of the New England Zoological Club
1760:
1589:Revision of the Pelycosauria of North America
1369:in a Permian Period landscape as depicted by
400:Researchers currently recognize two species:
8:
1424:Geological Society of America Special Paper
3372:
3207:
3070:
3059:
3046:
2852:
2755:
2626:
2622:
2535:
2531:
2518:
2408:
2193:
2180:
1980:
1948:
1944:
1933:
1920:
1862:
1835:
1826:
1783:
1767:
1753:
1745:
1396:. London: Marshall Editions. p. 187.
1379:Mural at the Yale Peabody Museum in 1947.
121:
20:
1732:
1528:
751:, named in 1878 by rival paleontologist
668:in New Mexico match the smaller size of
1312:Berman, D.S. (1977). "A New Species of
1261:
666:Prehistoric Trackways National Monument
420:are proportionately 45% taller than in
1447:
1445:
1417:
1415:
1413:
1269:
1267:
1265:
544:, although not as tall as the sail in
3555:Pennsylvanian genus first appearances
3515:Cisuralian synapsids of North America
522:Body proportions are also similar to
7:
471:, and early synapsids and diapsids.
332:(meaning "wedge point tooth") is an
3545:Taxa named by Othniel Charles Marsh
3535:Carboniferous geology of New Mexico
1689:Eberth, D.A. (1985). "The skull of
1084:
1060:
1036:
1011:
984:
926:
902:
877:
870:
351:periods. Like the closely related
14:
572:is allometrically larger than in
455:is known mainly from the east in
3356:
3355:
3322:
3032:
3026:
3020:
2504:
2499:
1530:10.1111/j.1475-4983.2011.01047.x
1220:
833:—or its own genus. The species "
602:
591:
361:was a carnivorous member of the
146:
1565:"Notice of new fossil reptiles"
798:with skeletal reconstructions.
136:Field Museum of Natural History
1:
3550:Fossil taxa described in 1878
3540:Permian geology of New Mexico
1721:Acta Palaeontologica Polonica
759:as a low-spined carnivorous "
664:tracks found in parts of the
3560:Cisuralian genus extinctions
719:
711:
703:
692:The American paleontologist
688:Restoration of two specimens
680:Discovery and classification
612:Size comparisons of species
3525:Carboniferous United States
3510:Prehistoric synapsid genera
1569:American Journal of Science
1069:Cryptovenator hirschbergeri
935:Palaeohatteria longicaudata
515:is very similar to that of
3576:
1045:Secodontosaurus obtusidens
853:(of uncertain placement).
813:is preoccupied by a fish (
503:Heavily restored skull of
16:Extinct genus of synapsids
3335:
3320:
3073:
3058:
3045:
3018:
2855:
2758:
2629:
2625:
2534:
2530:
2517:
2497:
2407:
2196:
1951:
1947:
1932:
1919:
1865:
1838:
1825:
1782:
1123:
1106:
1089:
1082:
1065:
1058:
1041:
1034:
1016:
1009:
989:
982:
965:
948:
931:
924:
907:
900:
882:
875:
303:
296:
251:
246:
143:Scientific classification
141:
129:
120:
23:
1392:Palmer, D., ed. (1999).
318:Williston and Case, 1913
3520:Carboniferous synapsids
1460:(Amniota: Synapsida)".
1318:Journal of Paleontology
952:Pantelosaurus saxonicus
803:Sphenacodon britannicus
465:Dimetrodon occidentalis
404:(the type species) and
769:Elcabrosaurus baldwini
689:
508:
3530:Permian United States
3477:Paleobiology Database
1734:10.4202/app.2010.0039
1462:Journal of Morphology
1297:Lucas, S. G. (2011).
911:Haptodus garnettensis
784:Alfred Sherwood Romer
687:
502:
1691:Sphenacodon ferocior
1563:Marsh, O.C. (1878).
788:Sphenacodon ferocior
618:Sphenacodon ferocior
570:Sphenacodon ferocior
418:Sphenacodon ferocior
410:Sphenacodon ferocior
406:Sphenacodon ferocior
1586:Case, E.C. (1907).
1521:2011Palgy..54..573H
1376:The Age of Reptiles
1236:List of pelycosaurs
1228:Paleontology portal
969:Ianthodon schultzei
807:Oxyodon britannicus
753:Edward Drinker Cope
507:in the Field Museum
1474:10.1002/jmor.10876
993:Cutleria wilmarthi
690:
509:
263:Marsh, 1878 (type)
3492:
3491:
3464:Open Tree of Life
3378:Taxon identifiers
3369:
3368:
3331:
3330:
3318:
3317:
3314:
3313:
3265:
3264:
3041:
3040:
3016:
3015:
3012:
3011:
3008:
3007:
3004:
3003:
2848:Sphenacodontoidea
2821:Palaeohatteriidae
2743:
2742:
2610:
2609:
2513:
2512:
2495:
2494:
2491:
2490:
2487:
2486:
2403:
2402:
2379:
2378:
2168:
2167:
2164:
2163:
1915:
1914:
1911:
1910:
1907:
1906:
1903:
1902:
1468:(12): 1407–1421.
1371:Rudolph Zallinger
1276:Sphenacodon ferox
1210:
1209:
1201:
1200:
1192:
1191:
1183:
1182:
1174:
1173:
1165:
1164:
1156:
1155:
1147:
1146:
1138:
1137:
1006:Sphenacodontoidea
823:Sphenacodon ferox
801:A third species,
777:Sphenacodon ferox
614:Sphenacodon ferox
431:Sphenacodon ferox
426:Sphenacodon ferox
422:Sphenacodon ferox
414:Sphenacodon ferox
402:Sphenacodon ferox
393:border region in
325:
324:
319:
311:
290:
285:S.(?) britannicus
277:
264:
242:
132:Sphenacodon ferox
3567:
3505:Sphenacodontidae
3485:
3484:
3472:
3471:
3459:
3458:
3446:
3445:
3433:
3432:
3420:
3419:
3418:
3405:
3404:
3403:
3373:
3359:
3358:
3326:
3302:
3292:
3282:
3213:
3208:
3178:
3146:
3120:
3094:
3079:
3071:
3060:
3047:
3036:
3030:
3024:
2878:Sphenacodontidae
2876:
2861:
2853:
2819:
2804:
2794:
2784:
2774:
2764:
2756:
2660:
2645:
2635:
2627:
2623:
2617:Haptodontiformes
2541:
2536:
2532:
2519:
2508:
2503:
2477:Protoclepsydrops
2474:
2464:
2454:
2444:
2434:
2424:
2409:
2194:
2186:
2181:
2120:Lalieudorhynchus
1981:
1973:
1957:
1949:
1945:
1934:
1921:
1863:
1836:
1827:
1820:
1819:
1784:
1769:
1762:
1755:
1746:
1739:
1738:
1736:
1718:
1709:
1703:
1702:
1686:
1680:
1679:
1667:
1661:
1660:
1648:
1642:
1641:
1635:
1633:
1628:
1619:
1613:
1612:
1600:
1594:
1593:
1583:
1577:
1576:
1560:
1554:
1553:
1541:
1535:
1534:
1532:
1500:
1494:
1493:
1449:
1440:
1439:
1436:10.1130/spe28-p1
1419:
1408:
1407:
1389:
1383:
1351:
1345:
1344:
1332:
1326:
1325:
1309:
1303:
1302:
1301:. pp. 1–48.
1294:
1288:
1287:
1271:
1230:
1225:
1224:
1223:
1085:
1061:
1037:
1031:Sphenacodontidae
1012:
985:
927:
903:
878:
871:
763:" distinct from
722:
714:
706:
606:
595:
367:Sphenacodontidae
317:
309:
288:
282:
275:
269:
262:
256:
237:
230:
219:Sphenacodontinae
217:
206:Sphenacodontidae
204:
151:
150:
125:
115:
52:
29:Temporal range:
21:
3575:
3574:
3570:
3569:
3568:
3566:
3565:
3564:
3495:
3494:
3493:
3488:
3480:
3475:
3467:
3462:
3454:
3449:
3441:
3436:
3428:
3423:
3414:
3413:
3408:
3399:
3398:
3393:
3380:
3370:
3365:
3327:
3310:
3261:
3232:
3197:
3171:
3139:
3113:
3087:
3067:
3054:
3037:
3000:
2980:
2944:Secodontosaurus
2869:
2842:
2812:
2787:Hypselohaptodus
2752:
2739:
2727:Remigiomontanus
2653:
2619:
2606:
2587:Stereophallodon
2543:Ophiacodontidae
2526:
2509:
2483:
2399:
2375:
2312:
2257:
2177:
2160:
2021:
1966:
1941:
1928:
1899:
1879:
1852:
1846:Tetrapodomorpha
1831:Tetrapodomorpha
1821:
1789:
1788:
1778:
1773:
1743:
1742:
1716:
1711:
1710:
1706:
1688:
1687:
1683:
1669:
1668:
1664:
1650:
1649:
1645:
1631:
1629:
1626:
1621:
1620:
1616:
1602:
1601:
1597:
1585:
1584:
1580:
1562:
1561:
1557:
1543:
1542:
1538:
1502:
1501:
1497:
1451:
1450:
1443:
1421:
1420:
1411:
1404:
1391:
1390:
1386:
1352:
1348:
1334:
1333:
1329:
1311:
1310:
1306:
1296:
1295:
1291:
1273:
1272:
1263:
1258:
1226:
1221:
1219:
1216:
1211:
1202:
1193:
1184:
1175:
1166:
1157:
1148:
1139:
863:after Fröbisch
771:Case, 1907 and
734:Rhynchocephalia
682:
624:
623:
622:
621:
609:
608:
607:
598:
597:
596:
497:
381:are known from
236:
228:
215:
202:
145:
116:
114:
113:
108:
103:
98:
93:
88:
83:
78:
73:
68:
63:
58:
47:
46:
27:
17:
12:
11:
5:
3573:
3571:
3563:
3562:
3557:
3552:
3547:
3542:
3537:
3532:
3527:
3522:
3517:
3512:
3507:
3497:
3496:
3490:
3489:
3487:
3486:
3473:
3460:
3447:
3434:
3421:
3406:
3390:
3388:
3382:
3381:
3376:
3367:
3366:
3364:
3363:
3353:
3348:
3343:
3336:
3333:
3332:
3329:
3328:
3321:
3319:
3316:
3315:
3312:
3311:
3309:
3308:
3298:
3288:
3277:
3275:
3272:Incertae sedis
3267:
3266:
3263:
3262:
3260:
3259:
3258:
3257:
3251:
3242:
3240:
3234:
3233:
3231:
3230:
3229:
3228:
3219:
3217:
3205:
3203:Eutheriodontia
3199:
3198:
3196:
3195:
3194:
3193:
3184:
3182:
3173:
3172:
3170:
3169:
3168:
3167:
3161:
3152:
3150:
3141:
3140:
3138:
3137:
3136:
3135:
3126:
3124:
3115:
3114:
3112:
3111:
3110:
3109:
3100:
3098:
3089:
3088:
3086:
3085:
3074:
3068:
3063:
3056:
3055:
3050:
3043:
3042:
3039:
3038:
3019:
3017:
3014:
3013:
3010:
3009:
3006:
3005:
3002:
3001:
2999:
2998:
2997:
2996:
2990:
2988:
2982:
2981:
2979:
2978:
2970:
2962:
2954:
2947:
2940:
2933:
2926:
2919:
2912:
2904:
2901:Ctenospondylus
2897:
2890:
2882:
2880:
2871:
2870:
2868:
2867:
2856:
2850:
2844:
2843:
2841:
2840:
2833:
2830:Palaeohatteria
2825:
2823:
2814:
2813:
2811:
2810:
2800:
2790:
2780:
2770:
2759:
2753:
2750:Sphenacodontia
2748:
2745:
2744:
2741:
2740:
2738:
2737:
2730:
2723:
2716:
2713:Melanedaphodon
2709:
2702:
2695:
2688:
2681:
2674:
2671:Bohemiclavulus
2666:
2664:
2662:Edaphosauridae
2655:
2654:
2652:
2651:
2641:
2630:
2620:
2615:
2612:
2611:
2608:
2607:
2605:
2604:
2597:
2590:
2583:
2576:
2569:
2562:
2555:
2547:
2545:
2528:
2527:
2522:
2515:
2514:
2511:
2510:
2498:
2496:
2493:
2492:
2489:
2488:
2485:
2484:
2482:
2481:
2470:
2460:
2450:
2440:
2430:
2419:
2417:
2414:Incertae sedis
2405:
2404:
2401:
2400:
2398:
2397:
2396:
2395:
2389:
2387:
2381:
2380:
2377:
2376:
2374:
2373:
2366:
2359:
2352:
2345:
2338:
2330:
2322:
2320:
2318:Varanodontinae
2314:
2313:
2311:
2310:
2303:
2296:
2289:
2282:
2275:
2267:
2265:
2263:Mesenosaurinae
2259:
2258:
2256:
2255:
2252:Thrausmosaurus
2248:
2241:
2233:
2226:
2219:
2212:
2209:Archaeovenator
2205:
2197:
2191:
2178:
2175:Eupelycosauria
2173:
2170:
2169:
2166:
2165:
2162:
2161:
2159:
2158:
2151:
2144:
2137:
2130:
2123:
2116:
2109:
2102:
2095:
2088:
2085:Cotylorhynchus
2081:
2074:
2067:
2060:
2053:
2046:
2039:
2031:
2029:
2023:
2022:
2020:
2019:
2012:
2005:
1998:
1989:
1987:
1978:
1968:
1967:
1965:
1964:
1960:Diadectomorpha
1952:
1942:
1937:
1930:
1929:
1924:
1917:
1916:
1913:
1912:
1909:
1908:
1905:
1904:
1901:
1900:
1898:
1897:
1896:
1895:
1889:
1887:
1881:
1880:
1878:
1877:
1876:
1875:
1873:Reptiliomorpha
1866:
1860:
1858:Reptiliomorpha
1854:
1853:
1851:
1850:
1849:
1848:
1839:
1833:
1823:
1822:
1818:
1817:
1808:
1802:
1796:
1787:
1780:
1779:
1774:
1772:
1771:
1764:
1757:
1749:
1741:
1740:
1727:(1): 113–120.
1704:
1681:
1662:
1643:
1614:
1595:
1578:
1575:(15): 409–411.
1555:
1536:
1515:(3): 573–590.
1495:
1441:
1409:
1402:
1384:
1346:
1327:
1304:
1289:
1260:
1259:
1257:
1254:
1253:
1252:
1245:
1238:
1232:
1231:
1215:
1212:
1208:
1207:
1204:
1203:
1199:
1198:
1195:
1194:
1190:
1189:
1186:
1185:
1181:
1180:
1177:
1176:
1172:
1171:
1168:
1167:
1163:
1162:
1159:
1158:
1154:
1153:
1150:
1149:
1145:
1144:
1141:
1140:
1136:
1135:
1132:
1131:
1122:
1119:
1118:
1115:
1114:
1110:Ctenospondylus
1105:
1102:
1101:
1098:
1097:
1088:
1083:
1081:
1078:
1077:
1074:
1073:
1064:
1059:
1057:
1054:
1053:
1050:
1049:
1040:
1035:
1033:
1027:
1026:
1023:
1022:
1015:
1010:
1008:
1002:
1001:
998:
997:
988:
983:
981:
978:
977:
974:
973:
964:
961:
960:
957:
956:
947:
944:
943:
940:
939:
930:
925:
923:
920:
919:
916:
915:
906:
901:
899:
897:Sphenacodontia
893:
892:
889:
888:
885:Edaphosauridae
881:
876:
874:
869:
851:incertae sedis
681:
678:
652:locomotion of
611:
610:
601:
600:
599:
590:
589:
588:
587:
586:
537:Ctenospondylus
496:
493:
363:Eupelycosauria
323:
322:
321:
320:
312:
301:
300:
294:
293:
292:
291:
289:(Huene, 1908)
278:
265:
249:
248:
244:
243:
226:
222:
221:
213:
209:
208:
200:
196:
195:
190:
183:
182:
177:
173:
172:
167:
163:
162:
157:
153:
152:
139:
138:
127:
126:
118:
117:
109:
104:
99:
94:
89:
84:
79:
74:
69:
64:
59:
54:
53:
28:
15:
13:
10:
9:
6:
4:
3:
2:
3572:
3561:
3558:
3556:
3553:
3551:
3548:
3546:
3543:
3541:
3538:
3536:
3533:
3531:
3528:
3526:
3523:
3521:
3518:
3516:
3513:
3511:
3508:
3506:
3503:
3502:
3500:
3483:
3478:
3474:
3470:
3465:
3461:
3457:
3452:
3448:
3444:
3439:
3435:
3431:
3426:
3422:
3417:
3411:
3407:
3402:
3396:
3392:
3391:
3389:
3387:
3383:
3379:
3374:
3362:
3354:
3352:
3349:
3347:
3346:Phthinosuchia
3344:
3342:
3338:
3337:
3334:
3325:
3307:
3306:
3299:
3297:
3296:
3289:
3287:
3286:
3279:
3278:
3276:
3274:
3273:
3268:
3256:
3252:
3250:
3246:
3245:
3244:
3243:
3241:
3239:
3235:
3227:
3226:Therocephalia
3223:
3222:
3221:
3220:
3218:
3216:
3215:Therocephalia
3209:
3206:
3204:
3200:
3192:
3188:
3187:
3186:
3185:
3183:
3181:
3174:
3166:
3162:
3160:
3156:
3155:
3154:
3153:
3151:
3149:
3142:
3134:
3130:
3129:
3128:
3127:
3125:
3123:
3116:
3108:
3104:
3103:
3102:
3101:
3099:
3097:
3090:
3084:
3083:
3076:
3075:
3072:
3069:
3066:
3061:
3057:
3053:
3048:
3044:
3035:
3031:
3029:
3023:
2994:
2993:
2992:
2991:
2989:
2987:
2983:
2976:
2975:
2974:Tetraceratops
2971:
2968:
2967:
2966:Tappenosaurus
2963:
2960:
2959:
2955:
2953:
2952:
2948:
2946:
2945:
2941:
2939:
2938:
2934:
2932:
2931:
2927:
2925:
2924:
2920:
2918:
2917:
2913:
2910:
2909:
2905:
2903:
2902:
2898:
2896:
2895:
2891:
2889:
2888:
2887:Cryptovenator
2884:
2883:
2881:
2879:
2872:
2866:
2865:
2858:
2857:
2854:
2851:
2849:
2845:
2839:
2838:
2837:Pantelosaurus
2834:
2832:
2831:
2827:
2826:
2824:
2822:
2815:
2809:
2808:
2807:Tetraceratops
2801:
2799:
2798:
2797:Kenomagnathus
2791:
2789:
2788:
2781:
2779:
2778:
2771:
2769:
2768:
2761:
2760:
2757:
2754:
2751:
2746:
2736:
2735:
2734:Xyrospondylus
2731:
2729:
2728:
2724:
2722:
2721:
2717:
2715:
2714:
2710:
2708:
2707:
2703:
2701:
2700:
2696:
2694:
2693:
2689:
2687:
2686:
2682:
2680:
2679:
2675:
2673:
2672:
2668:
2667:
2665:
2663:
2656:
2650:
2649:
2642:
2640:
2639:
2632:
2631:
2628:
2624:
2621:
2618:
2613:
2603:
2602:
2598:
2596:
2595:
2594:Stereorhachis
2591:
2589:
2588:
2584:
2582:
2581:
2577:
2575:
2574:
2570:
2568:
2567:
2563:
2561:
2560:
2556:
2554:
2553:
2552:Archaeothyris
2549:
2548:
2546:
2544:
2537:
2533:
2529:
2525:
2520:
2516:
2507:
2502:
2479:
2478:
2471:
2469:
2468:
2461:
2459:
2458:
2451:
2449:
2448:
2441:
2439:
2438:
2431:
2429:
2428:
2421:
2420:
2418:
2416:
2415:
2410:
2406:
2393:
2392:
2391:
2390:
2388:
2386:
2382:
2372:
2371:
2367:
2365:
2364:
2360:
2358:
2357:
2353:
2351:
2350:
2349:Tambacarnifex
2346:
2344:
2343:
2339:
2336:
2335:
2334:Mycterosaurus
2331:
2329:
2328:
2324:
2323:
2321:
2319:
2315:
2309:
2308:
2307:Microvaranops
2304:
2302:
2301:
2297:
2295:
2294:
2290:
2288:
2287:
2286:Elliotsmithia
2283:
2281:
2280:
2276:
2274:
2273:
2269:
2268:
2266:
2264:
2260:
2254:
2253:
2249:
2247:
2246:
2242:
2239:
2238:
2234:
2232:
2231:
2227:
2225:
2224:
2220:
2218:
2217:
2213:
2211:
2210:
2206:
2204:
2203:
2199:
2198:
2195:
2192:
2189:
2182:
2179:
2176:
2171:
2157:
2156:
2152:
2150:
2149:
2148:Ruthenosaurus
2145:
2143:
2142:
2141:Phreatophasma
2138:
2136:
2135:
2131:
2129:
2128:
2124:
2122:
2121:
2117:
2115:
2114:
2110:
2108:
2107:
2103:
2101:
2100:
2096:
2094:
2093:
2089:
2087:
2086:
2082:
2080:
2079:
2075:
2073:
2072:
2068:
2066:
2065:
2061:
2059:
2058:
2057:Callibrachion
2054:
2052:
2051:
2047:
2045:
2044:
2040:
2038:
2037:
2033:
2032:
2030:
2028:
2024:
2018:
2017:
2013:
2011:
2010:
2006:
2004:
2003:
1999:
1996:
1995:
1991:
1990:
1988:
1986:
1982:
1979:
1976:
1969:
1962:
1961:
1954:
1953:
1950:
1946:
1943:
1940:
1935:
1931:
1927:
1922:
1918:
1893:
1892:
1891:
1890:
1888:
1886:
1882:
1874:
1870:
1869:
1868:
1867:
1864:
1861:
1859:
1855:
1847:
1843:
1842:
1841:
1840:
1837:
1834:
1832:
1828:
1824:
1816:
1812:
1809:
1807:
1803:
1801:
1797:
1795:
1791:
1790:
1785:
1781:
1777:
1770:
1765:
1763:
1758:
1756:
1751:
1750:
1747:
1735:
1730:
1726:
1722:
1715:
1708:
1705:
1700:
1696:
1692:
1685:
1682:
1677:
1673:
1672:Palaeontology
1666:
1663:
1658:
1654:
1647:
1644:
1639:
1625:
1618:
1615:
1610:
1606:
1599:
1596:
1591:
1590:
1582:
1579:
1574:
1570:
1566:
1559:
1556:
1551:
1547:
1540:
1537:
1531:
1526:
1522:
1518:
1514:
1510:
1509:Palaeontology
1506:
1499:
1496:
1491:
1487:
1483:
1479:
1475:
1471:
1467:
1463:
1459:
1455:
1448:
1446:
1442:
1437:
1433:
1429:
1425:
1418:
1416:
1414:
1410:
1405:
1403:1-84028-152-9
1399:
1395:
1388:
1385:
1382:
1378:
1377:
1372:
1368:
1364:
1360:
1356:
1350:
1347:
1342:
1338:
1331:
1328:
1324:(1): 108–115.
1323:
1319:
1315:
1308:
1305:
1300:
1293:
1290:
1285:
1281:
1277:
1270:
1268:
1266:
1262:
1255:
1251:
1250:
1246:
1244:
1243:
1239:
1237:
1234:
1233:
1229:
1218:
1213:
1206:
1205:
1197:
1196:
1188:
1187:
1179:
1178:
1170:
1169:
1161:
1160:
1152:
1151:
1143:
1142:
1134:
1133:
1130:
1129:
1128:
1121:
1120:
1117:
1116:
1113:
1112:
1111:
1104:
1103:
1100:
1099:
1096:
1095:
1094:
1087:
1086:
1080:
1079:
1076:
1075:
1072:
1071:
1070:
1063:
1062:
1056:
1055:
1052:
1051:
1048:
1047:
1046:
1039:
1038:
1032:
1029:
1028:
1025:
1024:
1021:
1020:
1014:
1013:
1007:
1004:
1003:
1000:
999:
996:
995:
994:
987:
986:
980:
979:
976:
975:
972:
971:
970:
963:
962:
959:
958:
955:
954:
953:
946:
945:
942:
941:
938:
937:
936:
929:
928:
922:
921:
918:
917:
914:
913:
912:
905:
904:
898:
895:
894:
891:
890:
887:
886:
880:
879:
873:
872:
868:
866:
862:
858:
854:
852:
848:
844:
840:
836:
832:
828:
824:
820:
816:
812:
808:
804:
799:
797:
793:
789:
785:
780:
778:
774:
770:
766:
762:
758:
754:
750:
746:
741:
739:
735:
731:
727:
723:
721:
715:
713:
707:
705:
699:
695:
686:
679:
677:
675:
671:
667:
663:
659:
655:
650:
646:
642:
638:
633:
629:
619:
615:
605:
594:
585:
583:
579:
575:
571:
567:
562:
558:
554:
549:
547:
543:
539:
538:
533:
529:
525:
520:
518:
514:
511:The skull of
506:
501:
494:
492:
490:
486:
482:
478:
474:
470:
466:
462:
458:
454:
450:
446:
442:
438:
434:
432:
427:
423:
419:
415:
411:
407:
403:
398:
396:
395:North America
392:
388:
384:
380:
377:. Fossils of
376:
372:
368:
364:
360:
356:
355:
350:
346:
345:Carboniferous
342:
338:
335:
331:
330:
316:
313:
308:
307:Elcabrosaurus
305:
304:
302:
299:
295:
287:
286:
279:
274:
273:
266:
261:
260:
253:
252:
250:
245:
240:
235:
234:
227:
224:
223:
220:
214:
211:
210:
207:
201:
198:
197:
194:
191:
188:
185:
184:
181:
178:
175:
174:
171:
168:
165:
164:
161:
158:
155:
154:
149:
144:
140:
137:
133:
128:
124:
119:
112:
107:
102:
97:
92:
87:
82:
77:
72:
67:
62:
57:
51:
48:300–280
44:
40:
36:
32:
31:Pennsylvanian
26:
22:
19:
3385:
3351:Theriodontia
3341:Pelycosauria
3305:Niaftasuchus
3303:
3293:
3283:
3270:
3133:Dinocephalia
3122:Dinocephalia
3107:Biarmosuchia
3096:Biarmosuchia
3080:
3025:
2972:
2964:
2958:Steppesaurus
2956:
2950:
2949:
2942:
2935:
2928:
2921:
2914:
2906:
2899:
2894:Ctenorhachis
2892:
2885:
2862:
2835:
2828:
2805:
2795:
2785:
2775:
2765:
2732:
2725:
2718:
2711:
2704:
2699:Ianthasaurus
2697:
2690:
2685:Glaucosaurus
2683:
2678:Edaphosaurus
2676:
2669:
2646:
2636:
2601:Varanosaurus
2599:
2592:
2585:
2578:
2573:Echinerpeton
2571:
2564:
2557:
2550:
2475:
2465:
2455:
2445:
2435:
2425:
2412:
2368:
2361:
2354:
2347:
2340:
2332:
2325:
2305:
2300:Mesenosaurus
2298:
2291:
2284:
2277:
2270:
2250:
2243:
2235:
2228:
2221:
2216:Ascendonanus
2214:
2207:
2200:
2155:Trichasaurus
2153:
2146:
2139:
2132:
2125:
2118:
2111:
2104:
2099:Ennatosaurus
2097:
2092:Datheosaurus
2090:
2083:
2076:
2069:
2062:
2055:
2050:Arisierpeton
2048:
2043:Angelosaurus
2041:
2036:Alierasaurus
2034:
2014:
2007:
2000:
1992:
1985:Eothyrididae
1958:
1810:
1804:Superclass:
1724:
1720:
1707:
1698:
1694:
1690:
1684:
1675:
1671:
1665:
1656:
1652:
1646:
1638:ResearchGate
1636:– via
1630:. Retrieved
1617:
1608:
1604:
1598:
1588:
1581:
1572:
1568:
1558:
1549:
1545:
1539:
1512:
1508:
1498:
1465:
1461:
1457:
1453:
1427:
1423:
1393:
1387:
1374:
1366:
1363:Edaphosaurus
1362:
1358:
1354:
1349:
1340:
1336:
1330:
1321:
1317:
1313:
1307:
1298:
1292:
1283:
1279:
1275:
1247:
1242:Edaphosaurus
1240:
1125:
1124:
1108:
1107:
1092:
1091:
1090:
1067:
1066:
1043:
1042:
1017:
991:
990:
967:
966:
950:
949:
933:
932:
909:
908:
883:
864:
856:
855:
850:
846:
842:
838:
834:
830:
826:
822:
818:
814:
810:
806:
802:
800:
795:
791:
787:
781:
776:
772:
768:
764:
756:
748:
744:
742:
729:
725:
717:
709:
701:
700:(from Greek
697:
691:
673:
669:
661:
657:
653:
648:
644:
640:
636:
631:
627:
625:
617:
613:
582:Edaphosaurus
581:
577:
573:
569:
565:
560:
556:
552:
550:
545:
541:
535:
531:
527:
523:
521:
516:
512:
510:
504:
480:
479:. The genus
472:
464:
452:
448:
440:
436:
435:
430:
425:
421:
417:
413:
409:
405:
401:
399:
378:
374:
370:
358:
352:
328:
327:
326:
314:
306:
284:
283:
276:Romer, 1937
271:
270:
258:
257:
232:
231:
186:
131:
130:Skeleton of
24:
18:
3416:Sphenacodon
3410:Wikispecies
3386:Sphenacodon
3191:Gorgonopsia
3180:Gorgonopsia
3165:dicynodonts
3159:Anomodontia
3148:Anomodontia
2951:Sphenacodon
2930:Macromerion
2720:Ramodendron
2706:Lupeosaurus
2566:Clepsydrops
2559:Baldwinonus
2524:Metopophora
2467:Mastersonia
2457:Knoxosaurus
2385:Metopophora
2293:Heleosaurus
2188:Varanopidae
2016:Vaughnictis
1994:Asaphestera
1975:Caseasauria
1454:Sphenacodon
1355:Sphenacodon
1093:Sphenacodon
857:Sphenacodon
847:britannicus
843:Sphenacodon
839:britannicus
831:Sphenacodon
819:Sphenacodon
757:Sphenacodon
745:Sphenacodon
698:Sphenacodon
694:O. C. Marsh
670:Sphenacodon
654:Sphenacodon
637:Sphenacodon
628:Sphenacodon
616:and larger
566:Sphenacodon
561:Sphenacodon
553:Sphenacodon
542:Sphenacodon
532:Sphenacodon
513:Sphenacodon
495:Description
477:Wolfcampian
473:Sphenacodon
449:Sphenacodon
437:Sphenacodon
379:Sphenacodon
371:Sphenacodon
369:. However,
359:Sphenacodon
329:Sphenacodon
272:S. ferocior
233:Sphenacodon
212:Subfamily:
25:Sphenacodon
3499:Categories
3339:See also:
3295:Kamagorgon
3285:Dinosaurus
3249:Cynodontia
3238:Cynodontia
3065:Therapsida
3052:Therapsida
2995:see below↓
2986:Therapsida
2916:Dimetrodon
2864:Shashajaia
2648:Milosaurus
2580:Ophiacodon
2427:Dimacrodon
2394:see below↓
2342:Ruthiromia
2327:Aerosaurus
2237:Nitosaurus
2230:Dendromaia
2202:Apsisaurus
2127:Martensius
2113:Euromycter
1894:see below↓
1678:: 541–552.
1659:: 431–434.
1458:Dimetrodon
1367:Ophiacodon
1359:Dimetrodon
1353:Synapsids
1343:: 281–284.
1337:Dimetrodon
1314:Dimetrodon
1286:: 159–184.
1256:References
1127:Dimetrodon
1019:Therapsida
827:Dimetrodon
765:Dimetrodon
761:pelycosaur
749:Dimetrodon
716:"point" +
708:"wedge" +
674:Dimetrodon
662:Dimetropus
658:Dimetrodon
649:Dimetrodon
645:Dimetropus
641:Dimetrodon
632:Dimetrodon
578:Dimetrodon
557:Dimetrodon
546:Dimetrodon
528:Dimetrodon
524:Dimetrodon
517:Dimetrodon
485:therapsids
481:Dimetrodon
469:diadectids
453:Dimetrodon
441:Dimetrodon
383:New Mexico
375:Dimetrodon
354:Dimetrodon
347:and Early
310:Case, 1907
35:Cisuralian
3253:includes
3163:includes
3082:Raranimus
2937:Neosaurus
2638:Ianthodon
2363:Varanodon
2223:Eoscansor
2134:Oromycter
2078:Caseopsis
2071:Caseoides
2009:Oedaleops
1939:Synapsida
1926:Synapsida
1885:Synapsida
1806:Tetrapoda
1792:Kingdom:
1776:Synapsida
1430:: 1–538.
867:., 2011:
861:cladogram
782:In 1937,
773:Scoliomus
315:Scoliomus
193:Synapsida
166:Kingdom:
160:Eukaryota
43:Kungurian
3401:Q1050408
3395:Wikidata
3361:Category
2923:Eosyodon
2908:Cutleria
2777:Haptodus
2767:Cutleria
2692:Gordodon
2447:Gorgodon
2437:Driveria
2370:Watongia
2356:Varanops
2279:Cabarzia
2272:Anningia
2027:Caseidae
2002:Eothyris
1800:Chordata
1798:Phylum:
1794:Animalia
1611:: 89–96.
1552:: 67–69.
1490:40899700
1482:20886514
1249:Haptodus
1214:See also
796:ferocior
574:S. ferox
505:S. ferox
461:Oklahoma
385:and the
341:synapsid
298:Synonyms
259:S. ferox
247:Species
199:Family:
180:Chordata
176:Phylum:
170:Animalia
156:Domain:
39:Gzhelian
3456:1030918
3443:4819450
3430:4530679
3255:mammals
2106:Eocasea
1815:Amniota
1701:: 1–40.
1632:16 June
1517:Bibcode
841:(or as
835:Oxyodon
815:Oxyodon
811:Oxyodon
738:tuatara
489:mammals
445:Pangaea
391:Arizona
365:family
349:Permian
334:extinct
225:Genus:
134:in the
2245:Pyozia
1488:
1480:
1400:
1365:, and
696:named
241:, 1878
3482:38909
3469:78408
3451:IRMNG
2064:Casea
1811:Clade
1717:(PDF)
1627:(PDF)
1486:S2CID
865:et al
859:in a
792:ferox
730:ferox
720:odous
704:sphen
626:Both
457:Texas
337:genus
239:Marsh
187:Clade
3438:GBIF
3247:see
3224:see
3189:see
3157:see
3131:see
3105:see
1871:see
1844:see
1634:2024
1478:PMID
1456:and
1398:ISBN
1373:for
845:(?)
829:and
794:and
726:odon
656:and
639:and
630:and
580:and
555:and
459:and
439:and
387:Utah
56:PreꞒ
3425:EoL
1729:doi
1550:271
1525:doi
1470:doi
1466:271
1432:doi
712:ake
548:.)
339:of
45:),
41:to
33:to
3501::
3479::
3466::
3453::
3440::
3427::
3412::
3397::
1813::
1725:56
1723:.
1719:.
1699:90
1697:.
1676:17
1674:.
1657:14
1655:.
1609:16
1607:.
1571:.
1567:.
1548:.
1523:.
1513:54
1511:.
1507:.
1484:.
1476:.
1464:.
1444:^
1428:28
1412:^
1361:,
1357:,
1322:51
1320:.
1284:59
1282:.
1264:^
837:"
779:.
740:.
724:(-
676:.
647:("
584:.
491:.
408:.
397:.
357:,
189::
106:Pg
50:Ma
3301:†
3291:†
3281:†
3212:†
3177:†
3145:†
3119:†
3093:†
3078:†
2977:?
2969:?
2961:?
2911:?
2875:†
2860:†
2818:†
2803:†
2793:†
2783:†
2773:†
2763:†
2659:†
2644:†
2634:†
2540:†
2480:?
2473:†
2463:†
2453:†
2443:†
2433:†
2423:†
2337:?
2240:?
2190:?
2185:†
1997:?
1977:?
1972:†
1963:?
1956:†
1768:e
1761:t
1754:v
1737:.
1731::
1640:.
1573:3
1533:.
1527::
1519::
1492:.
1472::
1438:.
1434::
1406:.
620:.
389:–
281:†
268:†
255:†
229:†
216:†
203:†
111:N
101:K
96:J
91:T
86:P
81:C
76:D
71:S
66:O
61:Ꞓ
37:(
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