2755:
1372:
65:
2040:
1060:
2750:
409:
2772:
302:
1377:
1055:
42:
2035:
352:
is not a psammosteid pteraspidid, then the
Anchipteraspidids are the oldest-most known pteraspidid heterostracans, with three genera from Pridolian-aged strata from Upper Silurian Canada. The armor of anchipteraspidids superficially resemble those of cyathaspidids, though, anchipteraspidids already
365:
of
Protopteraspididae and Pteraspidoidei, and are sometimes treated as a suborder, "Psammosteoidei", or as an order-level taxon as "Psammosteida", or as a family, "Psammosteidae". Anatomically, a typical psammosteid resembles a typical pteraspidid that has had the forebody greatly dorsoventrally
372:, have the ventral shield modified into a pedestal-like structure that some researchers compare to a sled's runner. The psammosteids are the only heterostracans to survive beyond the Middle Devonian, as the last genera became extinct during the Late Devonian
567:
Botella, Hector, and
Richard A. Farina. "Flow pattern around the rigid cephalic shield of the Devonian agnathan Errivaspis waynensis (Pteraspidiformes: Heterostraci)." Palaeontology 51.5 (2008): 1141-1150.
579:
Purnell, Mark A. "Feeding in extinct jawless heterostracan fishes and testing scenarios of early vertebrate evolution." Proceedings of the Royal
Society of London B: Biological Sciences 269.1486 (2002):
603:
353:
have the typical series of plates diagnostic of pteraspidids, and the growth habits of anchipteraspidids are diagnostic of pteraspidids, and not of cyathaspidids.
471:
is thought to help with their hydrodynamic ability. Various genera are found in various marine and estuarine strata of Early
Devonian Europe and North America.
390:
Protopteraspididae was once thought to be a family of primitive or basal pteraspidids. A recent analysis of
Pteraspidiformes shows that Protopteraspididae is
1313:
329:. Delicate, finger-like components of the anterior end of the ventral plate forming the edges of the mouth suggest that pteraspidiform heterostracans were
1234:
240:
2602:
2567:
2185:
882:
2670:
1320:
926:
873:
833:
2613:
2546:
2504:
2323:
2262:
2242:
1957:
1500:
983:
245:
225:
220:
198:
188:
183:
2719:
2415:
2114:
2089:
1984:
1917:
1652:
1645:
1631:
1270:
789:
521:
168:
2839:
2698:
2663:
2574:
2426:
2271:
2130:
1777:
1465:
1421:
1160:
959:
935:
842:
782:
775:
718:
537:
497:
superficially resemble some genera of its sister taxon, Protaspididae, i.e., that they had armor shaped like a hot bun or a round loaf of bread.
193:
2525:
2296:
1933:
1507:
1493:
1486:
1180:
992:
891:
208:
2712:
2622:
2539:
2518:
2408:
2401:
2394:
2387:
2366:
2332:
2199:
2171:
2123:
2103:
2096:
1973:
1966:
1906:
1892:
1885:
1818:
1770:
1659:
1549:
1458:
1293:
1279:
1223:
999:
968:
485:
414:
2726:
2691:
2684:
2656:
2435:
2380:
2352:
2285:
2278:
2192:
2000:
1993:
1926:
1899:
1878:
1825:
1791:
1590:
1556:
1542:
1535:
1479:
1286:
1216:
1209:
747:
689:
543:
325:, a dorsal spine derived from a scale, and a large, scale-covered tail. Many genera were benthic, others were apparently active swimming
2649:
2560:
2553:
2178:
1811:
1528:
1514:
1243:
1189:
948:
858:
394:, as its various taxa show a gradual transition from primitive taxa similar to the Anchipteraspidids towards more derived taxa (such as
2705:
2677:
2007:
1784:
1694:
610:
515:
2935:
2900:
2754:
2359:
2915:
2905:
314:
A pteraspidiform heterostracan has the cephalothorax enclosed in armor, formed from several plates, including dorsal, ventral,
2925:
2930:
2920:
2910:
505:
Protaspididae is a family of bun or bread loaf-shaped pteraspidids found in Early
Devonian marine strata from the
382:
may or may not belong to this group; species of this genus superficially resemble a small, elongated psammosteid.
2890:
2885:
1371:
421:
Pteraspidoidei contains the more derived taxa within
Pteraspidiformes, though, some protopteraspidids, such as
2940:
64:
569:
581:
2830:
2039:
2880:
2775:
596:
1059:
2857:
2749:
2792:
2895:
2852:
467:, that are popularly thought to have actively swam about in the water column. The elongated
2844:
1261:
547:, a very compressed form that was originally described as a psammosteid closely related to
8:
2148:
2080:
815:
173:
163:
59:
1407:
1394:
1376:
1304:
1100:
709:
468:
315:
1948:
1840:
1338:
1054:
671:
658:
619:
373:
119:
2815:
1849:
1761:
1705:
506:
480:
322:
261:
441:
Pteraspididae is an Early
Devonian-aged family that contains the stereotypical,
2595:
2460:
2450:
2157:
2137:
1869:
1741:
1714:
1684:
1200:
738:
463:
330:
306:
215:
2874:
2633:
2481:
2343:
1802:
1674:
1604:
1433:
1327:
898:
796:
768:
429:
396:
283:
235:
230:
203:
2034:
489:, a genus of pteraspidids restricted to the Early Devonian marine strata of
2470:
2230:
2210:
1442:
1348:
1140:
1090:
1077:
1018:
917:
378:
362:
348:
319:
265:
178:
132:
2824:
2497:
2305:
2251:
2223:
1858:
1730:
1615:
1250:
1149:
700:
333:
that selectively filtered specific sized plankton from the water column.
408:
2581:
2511:
2312:
1750:
1723:
1638:
1567:
1472:
1451:
1169:
824:
761:
754:
643:
457:
446:
368:
271:
41:
2642:
2588:
2490:
2373:
2164:
1624:
1597:
1583:
851:
727:
531:
451:
423:
391:
301:
76:
50:
2786:
2809:
2532:
1576:
1521:
637:
588:
490:
287:
275:
96:
32:
28:
366:
depressed, with a long, compressed tail. Some psammosteids, like
442:
268:
106:
631:
510:
361:
The psammosteids are a group of pteraspidiforms that forms the
326:
290:
279:
86:
433:, share various features with these derived pteraspidids.
274:
known from extensive fossil remains primarily from Early
385:
2872:
1405:
881:
708:
2068:
925:
669:
604:
841:
1088:
541:, have armor that is more mound-shaped, or
376:). The Late Silurian-Early Devonian genus
611:
597:
40:
561:
407:
300:
2873:
573:
2791:
2790:
2055:
1393:
1392:
1075:
656:
592:
341:
2056:
657:
618:
13:
474:
445:-shaped pteraspidids, such as the
14:
2952:
403:
356:
2771:
2770:
2753:
2748:
2038:
2033:
1375:
1370:
1076:
1058:
1053:
500:
436:
400:) closer to the Pteraspidoidei.
63:
2936:Early Devonian taxonomic orders
2901:Prehistoric jawless fish orders
16:Extinct order of jawless fishes
2916:Silurian fish of North America
2906:Devonian fish of North America
1:
554:
509:of the United States, and of
483:family that was erected for
7:
10:
2957:
2926:Silurian first appearances
455:, and its close relatives
296:
2799:
2766:
2746:
2632:
2612:
2480:
2458:
2449:
2425:
2342:
2322:
2295:
2261:
2241:
2218:
2209:
2147:
2113:
2079:
2064:
2051:
2031:
1983:
1956:
1947:
1916:
1868:
1848:
1839:
1801:
1760:
1740:
1713:
1704:
1682:
1673:
1614:
1566:
1441:
1432:
1416:
1401:
1388:
1368:
1337:
1303:
1269:
1260:
1233:
1199:
1179:
1159:
1139:
1119:
1099:
1084:
1071:
1051:
1017:
982:
958:
943:
934:
916:
872:
832:
823:
814:
737:
717:
699:
684:
680:
665:
652:
626:
525:, are similar in form to
160:
155:
60:Scientific classification
58:
48:
39:
23:
2931:Pridoli taxonomic orders
529:, while others, such as
513:. Some genera, such as
2921:Silurian fish of Europe
2911:Devonian fish of Europe
336:
156:Suborders and families
418:
311:
27:Temporal range: Upper
2891:Silurian jawless fish
2886:Devonian jawless fish
2853:Paleobiology Database
479:Gigantaspididae is a
411:
304:
2941:Devonian extinctions
1262:Traquairaspidiformes
386:"Protopteraspididae"
1314:Pseudotraquairaspis
2149:Protopteraspididae
2081:Anchipteraspididae
1235:Tesseraspidiformes
816:Heterostracomorphi
419:
342:Anchipteraspididae
312:
241:Rhinopteraspididae
174:Protopteraspididae
164:Anchipteraspididae
2868:
2867:
2793:Taxon identifiers
2784:
2783:
2762:
2761:
2744:
2743:
2740:
2739:
2736:
2735:
2603:Stegobranchiaspis
2568:Mylopteraspidella
2445:
2444:
2186:Stegobranchiaspis
2047:
2046:
2029:
2028:
2025:
2024:
2021:
2020:
2017:
2016:
1943:
1942:
1835:
1834:
1669:
1668:
1408:Cyathaspidiformes
1395:Cyathaspidiformes
1384:
1383:
1366:
1365:
1362:
1361:
1358:
1357:
1305:Traquairaspididae
1101:Cyathaspidiformes
1067:
1066:
1049:
1048:
1045:
1044:
1041:
1040:
1037:
1036:
1013:
1012:
1009:
1008:
978:
977:
912:
911:
908:
907:
883:Tesakoviaspididae
868:
867:
810:
809:
806:
805:
710:Arandaspidiformes
286:, and from Upper
255:
254:
151:
2948:
2881:Pteraspidiformes
2861:
2860:
2848:
2847:
2835:
2834:
2833:
2831:Pteraspidiformes
2820:
2819:
2818:
2801:Pteraspidiformes
2788:
2787:
2774:
2773:
2757:
2752:
2671:Cyrtaspidichthys
2456:
2455:
2216:
2215:
2077:
2076:
2071:Pteraspidiformes
2066:
2065:
2058:Pteraspidiformes
2053:
2052:
2042:
2037:
1954:
1953:
1949:Siberiaspidoidei
1846:
1845:
1841:Hibernaspidoidei
1711:
1710:
1680:
1679:
1439:
1438:
1414:
1413:
1403:
1402:
1390:
1389:
1379:
1374:
1339:Weigeltaspididae
1321:Rimasventeraspis
1267:
1266:
1121:Pteraspidiformes
1097:
1096:
1086:
1085:
1073:
1072:
1062:
1057:
941:
940:
932:
931:
927:Eriptychiiformes
923:
922:
879:
878:
874:Tesakoviaspidida
839:
838:
834:Astraspidiformes
830:
829:
821:
820:
715:
714:
706:
705:
682:
681:
678:
677:
672:Pteraspidomorphi
667:
666:
659:Pteraspidomorphi
654:
653:
620:Pteraspidomorphi
613:
606:
599:
590:
589:
583:
577:
571:
565:
374:Kellwasser event
258:Pteraspidiformes
149:
146:Pteraspidiformes
144:
131:
120:Pteraspidomorphi
118:
68:
67:
44:
24:Pteraspidiformes
21:
20:
2956:
2955:
2951:
2950:
2949:
2947:
2946:
2945:
2871:
2870:
2869:
2864:
2856:
2851:
2843:
2838:
2829:
2828:
2823:
2814:
2813:
2808:
2795:
2785:
2780:
2758:
2732:
2628:
2614:Gigantaspididae
2608:
2547:Loricopteraspis
2505:Brachipteraspis
2476:
2441:
2421:
2338:
2324:Psammolepididae
2318:
2291:
2263:Guerichosteidae
2257:
2243:Drepanaspididae
2237:
2205:
2143:
2109:
2073:
2060:
2043:
2013:
1979:
1958:Siberiaspididae
1939:
1912:
1864:
1850:Hibernaspididae
1831:
1797:
1762:Gabreyaspididae
1756:
1736:
1706:Amphiaspidoidei
1700:
1665:
1610:
1562:
1501:Irregulareaspis
1428:
1410:
1397:
1380:
1354:
1333:
1299:
1256:
1229:
1195:
1175:
1155:
1135:
1115:
1093:
1080:
1063:
1033:
1005:
984:Oniscolepididae
974:
954:
904:
864:
802:
733:
695:
674:
661:
648:
622:
617:
587:
586:
578:
574:
566:
562:
557:
507:Rocky Mountains
503:
477:
475:Gigantaspididae
439:
412:Restoration of
406:
388:
359:
344:
339:
299:
246:Skalviaspididae
226:Larnovaspididae
221:Gigantaspididae
199:Psammolepididae
189:Guerichosteidae
184:Drepanaspididae
148:
142:
129:
116:
62:
35:
25:
17:
12:
11:
5:
2954:
2944:
2943:
2938:
2933:
2928:
2923:
2918:
2913:
2908:
2903:
2898:
2893:
2888:
2883:
2866:
2865:
2863:
2862:
2849:
2836:
2821:
2805:
2803:
2797:
2796:
2782:
2781:
2779:
2778:
2767:
2764:
2763:
2760:
2759:
2747:
2745:
2742:
2741:
2738:
2737:
2734:
2733:
2731:
2730:
2723:
2720:Woodfjordaspis
2716:
2709:
2702:
2695:
2688:
2681:
2674:
2667:
2660:
2653:
2646:
2638:
2636:
2630:
2629:
2627:
2626:
2618:
2616:
2610:
2609:
2607:
2606:
2599:
2596:Rhinopteraspis
2592:
2585:
2578:
2571:
2564:
2557:
2550:
2543:
2536:
2529:
2522:
2515:
2508:
2501:
2494:
2486:
2484:
2478:
2477:
2475:
2474:
2466:
2464:
2461:incertae sedis
2453:
2451:Pteraspidoidei
2447:
2446:
2443:
2442:
2440:
2439:
2431:
2429:
2423:
2422:
2420:
2419:
2416:Vladimirolepis
2412:
2405:
2398:
2391:
2384:
2377:
2370:
2363:
2356:
2348:
2346:
2340:
2339:
2337:
2336:
2328:
2326:
2320:
2319:
2317:
2316:
2309:
2301:
2299:
2293:
2292:
2290:
2289:
2282:
2275:
2267:
2265:
2259:
2258:
2256:
2255:
2247:
2245:
2239:
2238:
2236:
2235:
2227:
2219:
2213:
2207:
2206:
2204:
2203:
2196:
2189:
2182:
2175:
2168:
2161:
2158:Protopteraspis
2153:
2151:
2145:
2144:
2142:
2141:
2138:Semipodolaspis
2134:
2127:
2119:
2117:
2115:Podolaspididae
2111:
2110:
2108:
2107:
2100:
2093:
2090:Anchipteraspis
2085:
2083:
2074:
2069:
2062:
2061:
2049:
2048:
2045:
2044:
2032:
2030:
2027:
2026:
2023:
2022:
2019:
2018:
2015:
2014:
2012:
2011:
2004:
1997:
1989:
1987:
1985:Tuxeraspididae
1981:
1980:
1978:
1977:
1970:
1962:
1960:
1951:
1945:
1944:
1941:
1940:
1938:
1937:
1930:
1922:
1920:
1918:Aphataspididae
1914:
1913:
1911:
1910:
1903:
1896:
1889:
1882:
1874:
1872:
1870:Eglonaspididae
1866:
1865:
1863:
1862:
1854:
1852:
1843:
1837:
1836:
1833:
1832:
1830:
1829:
1822:
1815:
1807:
1805:
1799:
1798:
1796:
1795:
1788:
1781:
1774:
1766:
1764:
1758:
1757:
1755:
1754:
1746:
1744:
1742:Edaphaspididae
1738:
1737:
1735:
1734:
1727:
1719:
1717:
1715:Amphiaspididae
1708:
1702:
1701:
1699:
1698:
1690:
1688:
1685:incertae sedis
1677:
1671:
1670:
1667:
1666:
1664:
1663:
1656:
1653:Arctictenaspis
1649:
1646:Zaphoctenaspis
1642:
1635:
1632:Allocryptaspis
1628:
1620:
1618:
1612:
1611:
1609:
1608:
1601:
1594:
1587:
1580:
1572:
1570:
1564:
1563:
1561:
1560:
1553:
1546:
1539:
1532:
1525:
1518:
1511:
1504:
1497:
1490:
1483:
1476:
1469:
1462:
1455:
1447:
1445:
1436:
1430:
1429:
1427:
1426:
1417:
1411:
1406:
1399:
1398:
1386:
1385:
1382:
1381:
1369:
1367:
1364:
1363:
1360:
1359:
1356:
1355:
1353:
1352:
1344:
1342:
1335:
1334:
1332:
1331:
1324:
1317:
1309:
1307:
1301:
1300:
1298:
1297:
1290:
1283:
1275:
1273:
1271:Phialaspididae
1264:
1258:
1257:
1255:
1254:
1247:
1239:
1237:
1231:
1230:
1228:
1227:
1220:
1213:
1205:
1203:
1201:Tolypelepidida
1197:
1196:
1194:
1193:
1185:
1183:
1177:
1176:
1174:
1173:
1165:
1163:
1157:
1156:
1154:
1153:
1145:
1143:
1137:
1136:
1134:
1133:
1132:
1131:
1125:
1123:
1117:
1116:
1114:
1113:
1112:
1111:
1105:
1103:
1094:
1089:
1082:
1081:
1069:
1068:
1065:
1064:
1052:
1050:
1047:
1046:
1043:
1042:
1039:
1038:
1035:
1034:
1032:
1031:
1030:
1029:
1023:
1021:
1015:
1014:
1011:
1010:
1007:
1006:
1004:
1003:
996:
988:
986:
980:
979:
976:
975:
973:
972:
964:
962:
956:
955:
953:
952:
944:
938:
929:
920:
914:
913:
910:
909:
906:
905:
903:
902:
895:
887:
885:
876:
870:
869:
866:
865:
863:
862:
855:
847:
845:
836:
827:
818:
812:
811:
808:
807:
804:
803:
801:
800:
793:
790:Ritchieichthys
786:
779:
772:
765:
758:
751:
743:
741:
739:Arandaspididae
735:
734:
732:
731:
723:
721:
712:
703:
697:
696:
694:
693:
685:
675:
670:
663:
662:
650:
649:
647:
646:
640:
634:
627:
624:
623:
616:
615:
608:
601:
593:
585:
584:
572:
559:
558:
556:
553:
522:Woodfjordaspis
502:
499:
493:. Species of
476:
473:
464:Rhinopteraspis
438:
435:
405:
404:Pteraspidoidei
402:
387:
384:
358:
357:Psammosteoidei
355:
343:
340:
338:
335:
331:filter-feeders
307:Rhinopteraspis
298:
295:
260:is an extinct
253:
252:
251:
250:
249:
248:
243:
238:
233:
228:
223:
216:Pteraspidoidei
213:
212:
211:
206:
201:
196:
191:
186:
176:
171:
169:Podolaspididae
166:
158:
157:
153:
152:
140:
136:
135:
127:
123:
122:
114:
110:
109:
104:
100:
99:
94:
90:
89:
84:
80:
79:
74:
70:
69:
56:
55:
46:
45:
37:
36:
26:
15:
9:
6:
4:
3:
2:
2953:
2942:
2939:
2937:
2934:
2932:
2929:
2927:
2924:
2922:
2919:
2917:
2914:
2912:
2909:
2907:
2904:
2902:
2899:
2897:
2894:
2892:
2889:
2887:
2884:
2882:
2879:
2878:
2876:
2859:
2854:
2850:
2846:
2841:
2837:
2832:
2826:
2822:
2817:
2811:
2807:
2806:
2804:
2802:
2798:
2794:
2789:
2777:
2769:
2768:
2765:
2756:
2751:
2729:
2728:
2724:
2722:
2721:
2717:
2715:
2714:
2710:
2708:
2707:
2703:
2701:
2700:
2699:Tuberculaspis
2696:
2694:
2693:
2689:
2687:
2686:
2682:
2680:
2679:
2675:
2673:
2672:
2668:
2666:
2665:
2664:Europrotaspis
2661:
2659:
2658:
2654:
2652:
2651:
2647:
2645:
2644:
2640:
2639:
2637:
2635:
2634:Protaspididae
2631:
2625:
2624:
2620:
2619:
2617:
2615:
2611:
2605:
2604:
2600:
2598:
2597:
2593:
2591:
2590:
2586:
2584:
2583:
2579:
2577:
2576:
2575:Mylopteraspis
2572:
2570:
2569:
2565:
2563:
2562:
2558:
2556:
2555:
2551:
2549:
2548:
2544:
2542:
2541:
2537:
2535:
2534:
2530:
2528:
2527:
2523:
2521:
2520:
2516:
2514:
2513:
2509:
2507:
2506:
2502:
2500:
2499:
2495:
2493:
2492:
2488:
2487:
2485:
2483:
2482:Pteraspididae
2479:
2473:
2472:
2468:
2467:
2465:
2463:
2462:
2457:
2454:
2452:
2448:
2438:
2437:
2433:
2432:
2430:
2428:
2427:Obrucheviidae
2424:
2418:
2417:
2413:
2411:
2410:
2406:
2404:
2403:
2399:
2397:
2396:
2392:
2390:
2389:
2385:
2383:
2382:
2378:
2376:
2375:
2371:
2369:
2368:
2364:
2362:
2361:
2357:
2355:
2354:
2350:
2349:
2347:
2345:
2344:Psammosteidae
2341:
2335:
2334:
2330:
2329:
2327:
2325:
2321:
2315:
2314:
2310:
2308:
2307:
2303:
2302:
2300:
2298:
2294:
2288:
2287:
2283:
2281:
2280:
2276:
2274:
2273:
2272:Guerichosteus
2269:
2268:
2266:
2264:
2260:
2254:
2253:
2249:
2248:
2246:
2244:
2240:
2233:
2232:
2228:
2226:
2225:
2221:
2220:
2217:
2214:
2212:
2208:
2201:
2197:
2195:
2194:
2190:
2188:
2187:
2183:
2181:
2180:
2176:
2174:
2173:
2169:
2167:
2166:
2162:
2160:
2159:
2155:
2154:
2152:
2150:
2146:
2140:
2139:
2135:
2133:
2132:
2131:Parapteraspis
2128:
2126:
2125:
2121:
2120:
2118:
2116:
2112:
2106:
2105:
2101:
2099:
2098:
2094:
2092:
2091:
2087:
2086:
2084:
2082:
2078:
2075:
2072:
2067:
2063:
2059:
2054:
2050:
2041:
2036:
2010:
2009:
2005:
2003:
2002:
1998:
1996:
1995:
1991:
1990:
1988:
1986:
1982:
1976:
1975:
1971:
1969:
1968:
1964:
1963:
1961:
1959:
1955:
1952:
1950:
1946:
1936:
1935:
1931:
1929:
1928:
1924:
1923:
1921:
1919:
1915:
1909:
1908:
1904:
1902:
1901:
1897:
1895:
1894:
1890:
1888:
1887:
1883:
1881:
1880:
1876:
1875:
1873:
1871:
1867:
1861:
1860:
1856:
1855:
1853:
1851:
1847:
1844:
1842:
1838:
1828:
1827:
1823:
1821:
1820:
1816:
1814:
1813:
1809:
1808:
1806:
1804:
1803:Olbiaspididae
1800:
1794:
1793:
1789:
1787:
1786:
1782:
1780:
1779:
1778:Prosarctaspis
1775:
1773:
1772:
1768:
1767:
1765:
1763:
1759:
1753:
1752:
1748:
1747:
1745:
1743:
1739:
1733:
1732:
1728:
1726:
1725:
1721:
1720:
1718:
1716:
1712:
1709:
1707:
1703:
1697:
1696:
1692:
1691:
1689:
1687:
1686:
1681:
1678:
1676:
1675:Amphiaspidida
1672:
1662:
1661:
1657:
1655:
1654:
1650:
1648:
1647:
1643:
1641:
1640:
1636:
1634:
1633:
1629:
1627:
1626:
1622:
1621:
1619:
1617:
1613:
1607:
1606:
1605:Paraliliaspis
1602:
1600:
1599:
1595:
1593:
1592:
1588:
1586:
1585:
1581:
1579:
1578:
1574:
1573:
1571:
1569:
1565:
1559:
1558:
1554:
1552:
1551:
1547:
1545:
1544:
1540:
1538:
1537:
1533:
1531:
1530:
1526:
1524:
1523:
1519:
1517:
1516:
1512:
1510:
1509:
1505:
1503:
1502:
1498:
1496:
1495:
1491:
1489:
1488:
1484:
1482:
1481:
1477:
1475:
1474:
1470:
1468:
1467:
1466:Archegonaspis
1463:
1461:
1460:
1456:
1454:
1453:
1449:
1448:
1446:
1444:
1440:
1437:
1435:
1434:Cyathaspidida
1431:
1424:
1423:
1422:Nakaolinaspis
1419:
1418:
1415:
1412:
1409:
1404:
1400:
1396:
1391:
1387:
1378:
1373:
1351:
1350:
1346:
1345:
1343:
1340:
1336:
1330:
1329:
1328:Traquairaspis
1325:
1323:
1322:
1318:
1316:
1315:
1311:
1310:
1308:
1306:
1302:
1296:
1295:
1291:
1289:
1288:
1284:
1282:
1281:
1277:
1276:
1274:
1272:
1268:
1265:
1263:
1259:
1253:
1252:
1248:
1246:
1245:
1241:
1240:
1238:
1236:
1232:
1226:
1225:
1221:
1219:
1218:
1214:
1212:
1211:
1207:
1206:
1204:
1202:
1198:
1192:
1191:
1187:
1186:
1184:
1182:
1178:
1172:
1171:
1167:
1166:
1164:
1162:
1161:Lepidaspidida
1158:
1152:
1151:
1147:
1146:
1144:
1142:
1138:
1129:
1128:
1127:
1126:
1124:
1122:
1118:
1109:
1108:
1107:
1106:
1104:
1102:
1098:
1095:
1092:
1087:
1083:
1079:
1074:
1070:
1061:
1056:
1027:
1026:
1025:
1024:
1022:
1020:
1016:
1002:
1001:
997:
995:
994:
990:
989:
987:
985:
981:
971:
970:
966:
965:
963:
961:
960:Eriptychiidae
957:
951:
950:
946:
945:
942:
939:
937:
936:Eriptychiidae
933:
930:
928:
924:
921:
919:
915:
901:
900:
899:Tesakoviaspis
896:
894:
893:
889:
888:
886:
884:
880:
877:
875:
871:
861:
860:
856:
854:
853:
849:
848:
846:
844:
843:Astraspididae
840:
837:
835:
831:
828:
826:
822:
819:
817:
813:
799:
798:
797:Sacabambaspis
794:
792:
791:
787:
785:
784:
783:Porophoraspis
780:
778:
777:
776:Pircanchaspis
773:
771:
770:
769:Areyongalepis
766:
764:
763:
759:
757:
756:
752:
750:
749:
745:
744:
742:
740:
736:
730:
729:
725:
724:
722:
720:
719:Astraspididae
716:
713:
711:
707:
704:
702:
698:
692:
691:
687:
686:
683:
679:
676:
673:
668:
664:
660:
655:
651:
645:
641:
639:
635:
633:
629:
628:
625:
621:
614:
609:
607:
602:
600:
595:
594:
591:
582:
576:
570:
564:
560:
552:
550:
546:
545:
540:
539:
538:Tuberculaspis
534:
533:
528:
524:
523:
518:
517:
512:
508:
501:Protaspididae
498:
496:
492:
488:
487:
482:
472:
470:
469:rostral plate
466:
465:
460:
459:
454:
453:
448:
444:
437:Pteraspididae
434:
432:
431:
430:Panamintaspis
426:
425:
417:
416:
410:
401:
399:
398:
397:Panamintaspis
393:
383:
381:
380:
375:
371:
370:
364:
354:
351:
350:
334:
332:
328:
324:
321:
317:
309:
308:
303:
294:
292:
289:
285:
284:North America
281:
277:
273:
270:
267:
266:heterostracan
263:
259:
247:
244:
242:
239:
237:
236:Protaspididae
234:
232:
231:Pteraspididae
229:
227:
224:
222:
219:
218:
217:
214:
210:
207:
205:
204:Psammosteidae
202:
200:
197:
195:
194:Obrucheviidae
192:
190:
187:
185:
182:
181:
180:
177:
175:
172:
170:
167:
165:
162:
161:
159:
154:
147:
141:
138:
137:
134:
128:
125:
124:
121:
115:
112:
111:
108:
105:
103:Infraphylum:
102:
101:
98:
95:
92:
91:
88:
85:
82:
81:
78:
75:
72:
71:
66:
61:
57:
54:
52:
47:
43:
38:
34:
30:
22:
19:
2896:Heterostraci
2800:
2725:
2718:
2711:
2704:
2697:
2690:
2683:
2676:
2669:
2662:
2655:
2648:
2641:
2621:
2601:
2594:
2587:
2580:
2573:
2566:
2559:
2552:
2545:
2538:
2531:
2526:Grumantaspis
2524:
2517:
2510:
2503:
2496:
2489:
2471:Palanasaspis
2469:
2459:
2434:
2414:
2407:
2400:
2393:
2386:
2379:
2372:
2365:
2358:
2351:
2331:
2311:
2304:
2297:Pycnosteidae
2284:
2277:
2270:
2250:
2231:Weigeltaspis
2229:
2222:
2211:Psammosteida
2191:
2184:
2177:
2170:
2163:
2156:
2136:
2129:
2122:
2102:
2095:
2088:
2070:
2057:
2006:
1999:
1992:
1972:
1965:
1934:Putoranaspis
1932:
1925:
1905:
1898:
1891:
1884:
1877:
1857:
1824:
1817:
1810:
1790:
1783:
1776:
1769:
1749:
1729:
1722:
1693:
1683:
1658:
1651:
1644:
1637:
1630:
1623:
1603:
1596:
1589:
1582:
1575:
1555:
1548:
1541:
1534:
1527:
1520:
1513:
1508:Nahanniaspis
1506:
1499:
1494:Homaspidella
1492:
1487:Dinaspidella
1485:
1478:
1471:
1464:
1457:
1450:
1443:Cyathaspidae
1420:
1349:Weigeltaspis
1347:
1326:
1319:
1312:
1292:
1285:
1278:
1249:
1242:
1222:
1215:
1208:
1188:
1181:Corvaspidida
1168:
1148:
1141:Cardipeltida
1120:
1091:Heterostraci
1078:Heterostraci
1019:Heterostraci
998:
993:Kallostrakon
991:
967:
947:
918:Eriptychiida
897:
892:Kodinskaspis
890:
857:
850:
795:
788:
781:
774:
767:
760:
753:
746:
726:
688:
575:
563:
548:
542:
536:
530:
526:
520:
514:
504:
494:
484:
478:
462:
456:
450:
440:
428:
422:
420:
413:
395:
392:paraphyletic
389:
379:Weigeltaspis
377:
367:
363:sister taxon
360:
349:Weigeltaspis
347:
345:
313:
305:
257:
256:
209:Pycnosteidae
179:Psammosteida
145:
133:Heterostraci
49:
18:
2825:Wikispecies
2713:Zascinaspis
2623:Gigantaspis
2540:Larnovaspis
2519:Escharaspis
2498:Blieckaspis
2409:Selerolepis
2402:Rohonosteus
2395:Psarkosteus
2388:Psammosteus
2367:Karelosteus
2333:Psammosteus
2306:Tartuosteus
2252:Drepanaspis
2224:Tartuosteus
2200:Trygonaspis
2172:Escharaspis
2124:Dnestraspis
2104:Ulutitaspis
2097:Rhachiaspis
1974:Argyriaspis
1967:Siberiaspis
1907:Pelurgaspis
1893:Lecaniaspis
1886:Gerronaspis
1859:Hibernaspis
1819:Kureykaspis
1771:Gabreyaspis
1731:Amphoraspis
1660:Boothiaspis
1616:Ctenaspidae
1550:Torpedaspis
1459:Americaspis
1294:Toombsaspis
1280:Munchoaspis
1251:Tesseraspis
1224:Tolypelepis
1150:Cardipeltis
1000:Oniscolepis
969:Eriptychius
701:Arandaspida
642:Subphylum:
549:Drepanaspis
527:Gigantaspis
495:Gigantaspis
486:Gigantaspis
481:monogeneric
415:Larnovaspis
272:vertebrates
2875:Categories
2727:Pirumaspis
2692:Rodenaspis
2685:Psephaspis
2657:Lampraspis
2582:Podolaspis
2512:Errivaspis
2436:Obruchevia
2381:Placosteus
2353:Crenosteus
2313:Pycnosteus
2286:Pycnolepis
2279:Hariosteus
2193:Unkaraspis
2001:Litotaspis
1994:Tuxeraspis
1927:Aphataspis
1900:Empedaspis
1879:Eglonaspis
1826:Angaraspis
1792:Tareyaspis
1751:Edaphaspis
1724:Amphiaspis
1639:Alainaspis
1591:Listraspis
1568:Ariaspidae
1557:Veronaspis
1543:Steinaspis
1536:Seretaspis
1480:Dikenaspis
1473:Capitaspis
1452:Cyathaspis
1287:Phialaspis
1217:Athenaegis
1210:Asketaspis
1170:Lepidaspis
1130:see below↓
1110:see below↓
1028:see below↓
825:Astraspida
762:Arandaspis
755:Apedolepis
748:Andinaspis
690:Anatolepis
644:Vertebrata
555:References
544:Psephaspis
458:Errivaspis
447:type genus
369:Pycnosteus
278:strata of
126:Subclass:
2816:Q14545384
2650:Cosmaspis
2643:Protaspis
2589:Pteraspis
2561:Mitraspis
2554:Miltaspis
2491:Althaspis
2374:Osteoplax
2179:Miltaspis
2165:Doryaspis
1812:Olbiaspis
1625:Ctenaspis
1598:Liliaspis
1584:Anglaspis
1529:Ptomaspis
1515:Pionaspis
1244:Natlaspis
1190:Corvaspis
949:Eleochera
859:Pycnaspis
852:Astraspis
728:Astraspis
630:Kingdom:
532:Protaspis
452:Pteraspis
424:Doryaspis
150:Berg 1940
83:Kingdom:
77:Eukaryota
53:longiripa
51:Lamiaspis
2810:Wikidata
2776:Category
2706:Xylaspis
2678:Oreaspis
2533:Helaspis
2008:Dotaspis
1785:Pelaspis
1695:Gunaspis
1577:Ariaspis
1522:Poraspis
638:Chordata
636:Phylum:
632:Animalia
516:Xylaspis
491:Svalbard
288:Silurian
276:Devonian
269:agnathan
97:Chordata
93:Phylum:
87:Animalia
73:Domain:
33:Devonian
29:Silurian
443:torpedo
316:rostral
297:Anatomy
139:Order:
113:Class:
107:Agnatha
2858:149926
2360:Elgaia
580:83-88.
511:Europe
327:nekton
323:plates
320:pineal
310:fossil
291:Canada
280:Europe
2845:12527
2840:IRMNG
262:order
535:and
519:and
461:and
427:and
337:Taxa
282:and
346:If
264:of
2877::
2855::
2842::
2827::
2812::
551:.
449:,
318:,
293:.
2234:？
2202:"
2198:"
1425:？
1341:？
612:e
605:t
598:v
143:†
130:†
117:†
31:-
Text is available under the Creative Commons Attribution-ShareAlike License. Additional terms may apply.
