197:
477:
crowns of the dermal denticles on the first dorsal fin point forward and those on the head point backward, however it is unlikely that these were used for biting or tearing food. If the animal was disturbed by a potential predator while resting or feeding near the bottom it may have raised the head and tilted forward the first dorsal fin and spine, simulating a toothed open mouth of a much larger fish, therefore, an effective
36:
175:
319:
441:. This dorsal spine is fitted over a long basal plate and articulating at its base with the apex of a high triangular fin. The second dorsal fin is fitted over a very small, anterior basal plate apparently lacking a spine. The entire dorsal surface of head and first dorsal fin are covered with enlarged single cusped denticles. Secondary
320:
493:
Teeth are typical cladodont in form. They are composed of 5 cusps, the central being the largest, the two extreme lateral smaller, and the intermediate very small. Cusps are rounded in cross section, slightly curved inwards and strongly striated vertically. Modified denticles cover the dorsal surface
654:
Stethacanthids are a very derived group of
Paleoselachii sharks, defined by a highly modified first dorsal fin (only in adult males) and strong sexual dimorphism. This condition is also seen in symmoriids and is unique among known elasmobranchs of any time. So, either symmoriids are the females of
456:
The first dorsal fin is one of the strangest features of these fish. The fin itself is triangular and is composed of long, thin, calcified tubes radiating from the apex. The posterior dorsal surface of the first dorsal fin is covered with a belt of up to nine rows of enlarged dermal denticles. The
476:
A shark with a structure on its back, such as a stethacanthid, could not have possibly been a fast swimmer. The first dorsal fin and spine could have produced a considerable amount of drag during fast locomotion. This suggests that
Stethacanthids may have been rather sluggish bottom dwellers. The
630:
with copulation. During the
Carboniferous chondrichthyans radiated rapidly and expansively in all available aquatic regimes and some of the most bizarre forms originated during this period. Stethacanthids are classified within the division Paleoselachii, of the Subclass
554:
that is unique in preserving virtually an entire small marine bay of extremely brief duration in the late
Mississippian (Heath Formation, Palaeozoic; 323Ma). During deposition, it was located approximately 12ºN latitude and was part of an extensive
464:, is roughly a right triangle in shape, with the hypothenuse concave anterodorsally. The trabecular dentine contains a large number of fibres in the dorsal half of the spine. This suggests that, in live, a large portion of the spine was covered by
361:) rocks of the mid-continental United States. Decomposition of the internal cartilage and compression during burial resulted in distortion of the spines, leading Newberry to misinterpret them, he believed that the spines belonged to
381:
evolution that is significantly divergent enough to warrant family-level separation". This classification was later corroborated by another authors (e.g. Zangerl, 1990). Further reports of material attributed to
502:
bases and are fitted together in a mosaic pattern. In the male, the denticles increase in height and decrease in curvature toward the midline of the fin, so that the central denticles reach 2 cm in height.
1127:
GROGAN, E.D., LUND, R. & GREENFEST-ALLEN, E., 2012. The Origin and
Relationships of Early Chondrichthyans. In CARRIER, J.C., MUSICK, J.A. & HEITHAUS, M.R. (eds.), Biology of Sharks and their Relatives.
659:
The classification of symoriiform sharks (including the
Families Stethacanthidae, Symmoriidae and Falcatidae) will remain a controversy until other complete specimens are found outside of the Bear Gulch lens.
1073:
WITZKE, B.J., 1990. Paleoclimatic constraints for
Paleozoic paleoaltitudes of Laurentia and Euroamerica. In: McKERROW, W.S. & SCOTESE, C.R. (eds.), Paleozoic Paleogeography and Biogeography.
337:
The taxonomic history of the Family
Stethacanthidae has been rather complicated because the findings of complete skeletons are very unusual, and as result early workers such as St. John &
498:. The denticles on the head are relatively uniform in size (about as high as the central cusps in the teeth), and rounded in cross section. The denticles on the edge of the dorsal fin have
690:
Coates, M., Gess, R., Finarelli, J., Criswell, K., Tietjen, K. 2016. A symmoriiform chondrichthyan braincase and the origin of chimaeroid fishes. Nature. doi: 10.1038/nature20806
514:
fall into two types. The first, thought to be the primitive condition, bears virtually the entire pelvic fin. The second, consists of a prominent metapterygial plate. The
1107:
GROGAN, E.D. & LUND, R., 2002. The geological and biological environment of the Bear Gulch
Limestone (Mississippian of Montana, USA) and a model for its deposition.
969:
1238:
1056:
LUND, R., GREENFEST-ALLEN, E. & GROGAN, E.D., 2012. Habitat and diversity of the Bear Gulch fish: Life in a 318 million year old marine
Mississippian bay.
373:
and Mississippian of Ohio, were not described until a century later. The Family Stethacanthidae was described by Richard Lund in 1974, he argued that "
311:. It is estimated to have existed approximately between 380 and 300 million years ago. Members of this family are noted for their peculiar dorsal fin.
1294:
57:
44:
1279:
1225:
1145:
MAISEY, J.G., 2009. The spine-brush complex in Symmoriiform sharks (Chondrichthyes: Symmoriiformes), with comments on dorsal fin modularity.
1289:
1299:
706:
COATES, M.I. & SEQUEIRA, S.E.K., 2001. A new stethacanthid chondrichthyan from the lower Carboniferous of Bearsden, Scotland,
1090:
GUTHRIE, G.E., 1985. Stratigraphy and depositional environment of Upper Mississippian Big Snow group, Bridger Range, Montana.
1284:
1010:
ROSEN, D.E., FOREY, P.L., GARDINER, B.G. & PATTERSON, C., 1981. Lungfishes, tetrapods, palaeontology, and plesiomorphy.
196:
481:. However, only males possessed the "armoured" first dorsal fin and spine, and this suggests that the function was merely
635:. On a lower taxonomical level, the classification of this group is very controversial. There are two main hypothesis:
1036:
LUND, R., 1967. An analysis of the propulsive mechanisms of fishes, with reference to some fossil actinopterygians.
591:
of this formation indicates that it was deposited under variable conditions of salinity with seasonal periodicity.
940:"Late Devonian and Early Carboniferous chondrichthyans from the Fairfield Group, Canning Basin, Western Australia"
49:
822:
WILLIAMS, M.E., 1985. The «cladodont level» sharks of the Pennsylvanian black shales of central North America.
183:
802:
LUND, R., 1985a. Stethacanthid elasmobranch remains from the Bear Gulch Limestone (Namurian E2b) of Montana.
1304:
369:
of a new species of shark. The first associated skeletal remains, from the Mississippian of Montana and the
1165:
900:
LEBDEV, O.A., 1996. Fish assemblages of the Tounaisian-Viséan environments of the East European Platform.
627:
1251:
963:
333:, University of Glasgow). Photograph taken by Dr. Keith Ingham, published in Coates & Sequira, 2001.
920:
WOOD, S.P., 1982. New basal Namurian (Upper Carboniferous) fishes and crustaceans found near Glasgow.
286:
1212:
1203:
584:
547:
414:
358:
94:
989:
ZANGERL, R., 1984. On the microscopic anatomy and possible function of the spine-"brush" complex of
572:
518:, in the male, are separated from the body of the fin by about four blocks of calcified cartilage.
494:
of the head and upper edge of dorsal fin. Both sets of denticles are smooth, monocuspid and curved
338:
191:
1256:
478:
465:
442:
422:
354:
1243:
951:
587:(Serpukhovian) in Bearsden near Glasgow, Scotland. As well as the Bear Gulch Limestone, the
330:
341:, and Newberry were unable to recognise the association of the spine, dentition teeth, and
342:
622:
forms is still poorly understood. Chondrichthyes are distinguished based on a two unique
648:
632:
607:
599:
576:
551:
511:
482:
430:
308:
251:
238:
86:
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bears a large, thin walled compressed spine, displaying no ornamentation and concave
429:
region, and short otic region. The teeth on jaws are of cladodont type, displaying 5
293:
132:
90:
842:
ZANGERL, R., 1981. Chondrichthyes I: Paleozoic Elasmobranchii. H.P. Schultze (ed.),
567:
input and was opened to the East. It is likely that the diversity of the Bear Gulch
426:
623:
603:
531:
410:
395:
378:
362:
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to it. The most complete skeleton ever found has been published recently from the
1197:
640:
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387:
366:
325:
279:
107:
1188:
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619:
535:
527:
458:
438:
434:
152:
117:
938:
Brett Roelofs, Milo Barham, Arthur J. Mory, Kate Trinajstics (January 2016).
579:
forms and the bay likely provided breeding and nursery grounds for those not
417:
characters best represented in this species. Stethacanthids are medium-sized
17:
626:
character sets: the development of tesserae endoskeletal mineralisation and
588:
560:
499:
418:
350:
208:
157:
101:
35:
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of the family Stethacanthidae, therefore, all stethacanthids meet certain
1182:
670:
615:
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391:
370:
228:
147:
142:
127:
122:
112:
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shark (Elasmobranchii, Symmoriida) from the Mississippian of Oklahoma.
726:
St. JOHN, O. & WORTHEN, A.H., 1875. Descriptions of fossil fishes.
580:
564:
461:
162:
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was established by Newberry (1889) for a series of large thin walled,
556:
218:
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have extended its range to the Mississippian of Oklahoma, the Lower
568:
318:
955:
1217:
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29:
748:
NEWBERRY, J.S., 1889. The Paleozoic fishes of North America.
782:(Elasmobranchii) from the Bear Gulch Limestone of Montana.
655:
some stethacanthids, or they are derived from this group.
445:
is present, only mature males bear a first dorsal fin.
614:, and the extant chondrichthyans are derivable from
1172:
1012:Bulletin of the American Museum of Natural History
1058:Palaeogeography, Palaeoclimatology, Palaeoecology
858:ZANGERL, R., 1990. Two new stethacanthid sharks (
563:climatic regime. The bay was subject to minimal
618:forms. Yet, the relationship of these with the
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968:: CS1 maint: multiple names: authors list (
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575:marine faunas, due to the accessibility to
468:, probably anchoring the first dorsal fin.
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862:) from the Pennsylvanian of Indiana, USA.
798:
796:
774:
772:
770:
768:
766:
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606:group divisible into two sister taxa, the
173:
78:
750:United States Geological Survey Monograph
546:Most Stethacanthids found come from the
60:of all important aspects of the article.
683:
421:shark-like holocephalians with a short
961:
902:Geological Society Special Publication
844:Handbook of Paleoichthyology, New York
56:Please consider expanding the lead to
27:Extinct family of cartilaginous fishes
7:
307:is an extinct family of prehistoric
824:Palaeontographica Band A, Stuttgart
1147:Journal of Vertebrate Paleontology
995:Journal of Vertebrate Paleontology
708:Journal of Vertebrate Paleontology
25:
1295:Carboniferous cartilaginous fish
550:of Montana. The Bear Gulch is a
390:of Central Russia and the basal
195:
34:
1280:Late Devonian first appearances
48:may be too short to adequately
993:(Elasmobranchii: Symmoriida).
651:and form a monophyletic group.
647:are included within the Order
534:, but approaches a functional
58:provide an accessible overview
1:
728:Geological Survey of Illinois
559:environment and subjected to
353:-cored spines encountered in
377:represents an experiment in
1290:Devonian cartilaginous fish
860:Stethacanthidae, Symmoriida
507:Pelvic girdles and claspers
345:of these sharks. The genus
1321:
1075:Geological Society Memoirs
944:Palaeontologia Electronica
452:First dorsal fin and spine
433:(pentacuspids). The first
1300:Pennsylvanian extinctions
1038:Annals of Carnegie Museum
879:ZIDEK, J., 1993. A large
804:American Museum Novitates
784:Annals of Carnegie museum
571:may be representative of
275:
270:
192:Scientific classification
190:
181:
172:
81:
1027:LUND, R., 1984, in press
864:Palaeontographica Band A
780:Stethacanthus altonensis
407:Stethacanthus altonensis
184:Stethacanthus altonensis
595:Taxonomic relationships
885:Oklahoma Geology Notes
643:, Stethacanthidae and
628:internal fertilisation
334:
1285:Late Devonian animals
1252:Paleobiology Database
323:Complete skeleton of
322:
585:Manse Burn Formation
548:Bear Gulch Limestone
359:Carboniferous Period
326:Akmonistion zangerli
95:Middle Pennsylvanian
573:upper Mississippian
489:Teeth and denticles
457:spine, composed of
335:
1267:
1266:
1166:Taxon identifiers
479:defence mechanism
466:connective tissue
443:sexual dimorphism
302:
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100:382.7–323.2
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16:(Redirected from
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778:LUND, R., 1974.
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343:dermal denticles
331:Hunterian Museum
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85:Temporal range:
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1174:Stethacanthidae
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305:Stethacanthidae
265:Stethacanthidae
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43:This article's
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1305:Symmoriiformes
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649:Symmoriiformes
633:Elasmobranchii
624:autapomorphous
608:Elasmobranchii
600:Chondrichthyes
596:
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543:
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512:Pelvic girdles
508:
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483:sexual display
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309:holocephalians
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252:Symmoriiformes
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87:Upper Devonian
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52:the key points
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1092:AAPG Bulletin
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881:stethacanthid
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639:The Families
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415:morphological
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398:of Scotland.
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389:
385:
384:Stethacanthus
380:
376:
375:Stethacanthus
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368:
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355:Mississippian
352:
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347:Stethacanthus
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91:Carboniferous
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66:November 2014
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32:
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19:
18:Stethacanthid
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1069:
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1057:
1041:
1037:
1032:
1023:
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994:
991:Stehacanthus
990:
964:cite journal
956:10.26879/583
947:
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933:
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905:
901:
896:
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863:
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843:
827:
823:
807:
803:
787:
783:
779:
753:
749:
731:
727:
711:
707:
686:
669:
658:
604:monophyletic
598:
545:
532:heterocercal
525:
510:
492:
475:
455:
447:
427:supraorbital
411:type species
406:
405:
396:Serpukhovian
383:
379:elasmobranch
374:
346:
336:
324:
315:Introduction
304:
303:
292:
285:
278:
264:
182:
76:
63:
47:
45:lead section
1198:Wikispecies
950:(1): 1-28.
641:Symmoriidae
612:Holocephali
552:lagerstätte
542:Environment
538:condition.
496:posteriorly
402:Description
388:Tournaisian
367:pelvic fins
280:Akmonistion
1274:Categories
678:References
645:Falcatidae
620:Palaeozoic
536:homocercal
528:caudal fin
522:Caudal fin
459:trabecular
439:anteriorly
435:dorsal fin
329:(HMV8246,
1115:, 295-315
1044:, 195-218
1018:, 150-276
1001:, 372-378
928:, 574-577
908:, 387-415
870:, 115-141
790:, 161-178
734:, 245-488
714:, 438-459
589:lithology
577:migratory
561:monsoonal
500:polygonal
419:cladodont
351:cartilage
215:Kingdom:
209:Eukaryota
50:summarize
1189:Q1339753
1183:Wikidata
830:, 83-158
756:, 340pp.
671:Falcatus
664:See also
616:Mesozoic
516:claspers
472:Function
425:, broad
392:Namurian
371:Devonian
363:pectoral
287:Damocles
258:Family:
229:Chordata
225:Phylum:
219:Animalia
205:Domain:
1231:4824087
1218:4655571
1153:, 14-24
1081:, 57-73
1062:342-343
846:, 115pp
581:endemic
565:fluvial
462:dentine
423:rostrum
409:is the
339:Worthen
271:Genera
245:Order:
235:Class:
1257:151645
1244:103332
1136:, 3-29
1064:, 1-16
1042:39(15)
922:Nature
891:, 4-15
810:, 1-24
557:sabkha
1239:IRMNG
1151:29(1)
788:45(8)
712:21(3)
602:is a
569:fauna
431:cusps
1226:GBIF
999:4(3)
970:link
808:2828
732:6(2)
610:and
526:The
365:and
108:PreꞒ
1213:EoL
1098:, 5
1016:167
952:doi
926:291
906:107
868:213
828:190
530:is
97:),
89:to
1276::
1254::
1241::
1228::
1215::
1200::
1185::
1149:,
1132:,
1120:^
1113:24
1111:,
1096:69
1094:,
1079:12
1077:,
1060:,
1049:^
1040:,
1014:,
997:,
978:^
966:}}
962:{{
948:19
946:.
942:.
924:,
913:^
904:,
889:53
887:,
866:,
851:^
835:^
826:,
815:^
806:,
795:^
786:,
761:^
754:16
752:,
739:^
730:,
719:^
710:,
695:^
485:.
158:Pg
102:Ma
1134:1
972:)
958:.
954::
394:/
357:(
262:†
249:†
163:N
153:K
148:J
143:T
138:P
133:C
128:D
123:S
118:O
113:Ꞓ
93:(
68:)
64:(
54:.
20:)
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