scan01a.jpg (22603 bytes)

A new Ctenacanthus amblyxiphias discovery from the Permian of Kansas (when most of Kansas was covered by a much earlier ocean)

ctenaca3.jpg (32094 bytes)


Copyright © 2002-2009 by Mike Everhart

Page created 08/28/2002; Last updated 07/24/2009

The dorsal fin spines of Ctenacanthus sharks are found in marine deposits from Devonian through Permian time.  As shown above, Ctenacanthids have a pair of rigid fin spines that emerge in front of each of two dorsal fins. The name Ctenacanthus literally means "comb-spine" and comes from the distinctive comb-like appearance of the two fin spines. The dorsal fin spines are ornamented with thin rows of dentine-like material that looks like strings of tiny beads in some areas.  Ctenacanthid spines were sub-cylindrical and pointed and, in life, were supported by a wedge of cartilage that inserted into a groove on the posterior side of the fin spine.

Ctenacanthus Agassiz 1835 is part of the order Euselachii Hay (1902).  According to Zangerl (1981, p. 51),  "The Paleozoic members of this group are readily identified as having two dorsal fins, each preceded by a basically neo-selachian finspine whose apical end protrudes beyond the epidermis, and is finished by an outer coat of orthodentine that also forms the ornamentation (Maisey, 1975). Each spine is supported by a triangular cartilage piece that reaches into its central cavity from behind. The radials of the paired fins and the ventral lobe of the caudal fin are usually undivided transversally, and there is little difference in the size and robustness of the anterior and posterior radials.  One anal fin is present.  The shape of the body is fusiform. The integument is armored with placoid denticles and/or aggregates of modified lepidomorial denticles."

Wayne Itano provided the early identification of this specimen to species (Ctenacanthus amblyxiphias Cope 1891).  For Cope's 1891 description and figures, and for more information about Ctenacanthus, go to the bottom of the page. The follow paper (abstract) was presented at the 135 Annual meeting of the Kansas Academy of Sciences (4th Annual Paleontology Symposium), at Pittsburg State University, Pittsburg, KS.

Since this page was first created, Keith Ewell has discovered a number of Early Permian ctenacanth spines and sharks teeth in Geary and Wabaunsee counties, near Manhattan, Kansas. See them here.

Everhart, M. J. and P. A. Everhart, 2003. First report of the Paleozoic shark, Ctenacanthus amblyxiphias Cope 1891 from the Lower Permian of Morris County Kansas. Kansas Acad. of Science Abstracts, 22:13.


In August, 2002, the remains of a small (1.6 m) Paleozoic shark (FHSM VP-15012) were discovered eroding from an exposure of the Grant Member of the Winfield Formation (Chase Group, Wolfcampian Series, Lower Permian) in the northeast corner of Morris County, Kansas. The matrix surrounding the specimen is a fine-grained, calcitic mudrock that is interpreted as a near-shore, shallow water deposit. The remains include the anterior and posterior dorsal fin spines, several pieces of calcified cartilage, including the left(?) scapulo-coracoid, placoid and ganoid scales, and placodont teeth. The nearly complete, anterior and posterior dorsal fin spines measure 25 and 18 cm in length. The fin spines are distinctively ornamented with thin rows of dentine-like material. The remains were identified as Ctenacanthus amblyxiphias by comparison with the dorsal fin spine described by Cope from the Redbeds (Permian) of Texas. Abundant shells of the brachiopod Composita subtilata, as well as silicified echinoid spines, ramose bryozoans, and crinoid fragments were associated with the remains. A crinoid calyx, provisionally identified as Delocrinus brownvillensis, was discovered nearby at the same stratigraphic level. A review of the literature and museum collections indicates that this is the first report of this shark species from Kansas.

This webpage is a somewhat radical departure from the usual Late Cretaceous fossils normally featured on Oceans of Kansas. The much older Permian is well represented in Kansas, but is somewhat less fossiliferous than in other Midwest states such as Oklahoma and Texas. Go HERE for a map of the Earth during the Late Permian (large file- See the Paleomap Project for more paleo-maps of the Earth)

site200a.jpg (7560 bytes) 1) On August 17, 2002, my wife and I were returning from a meeting in Manhattan, Kansas when we decided to stop and prospect a road cut north of Herington (northwest corner of Morris County). I had been there twice before and knew that there were lots of invertebrate remains (mostly Composita brachiopods) weathering from an exposure of the Winfield Formation (Early Permian). The Winfield Fm. is part of the lower middle Permian Chase Group (Wolfcampian series)  in central Kansas, and was deposited as limey bottom muds in the ocean that covered Kansas about 270 million years ago. The top of the underlying Doyle formation is exposed at the extreme left of the picture. The shark remains came from the Grant Member of the Winfield Fm. just to the left of center (A big "Thank You" to Dr. Salvadore Mazzullo at Wichita State University for the confirmation of the site stratigraphy). 
ctena00a.jpg (14554 bytes) 2) This is a representative sample of the invertebrate remains, including a crinoid calyx, a single Reticulatia productid brachiopod and multiple Composita subtilata brachiopods, that I had collected earlier from the site. (Scale = mm).  A larger picture of the Reticulatia sp. shell is HERE. Note that there are at least three small Composita brachs preserved inside the Reticulatia shell. Other smaller invertebrate remains are shown HERE, including echinoid spines, bryozoan fragments and crinoid stem fragments.

Two larger pictures of the crinoid calyx are HERE and HERE (A "thank you" for the suggestion to Earl Manning and Peter Holterhoff.)  Peter thought that the crinoid might be Delocrinus brownsvillensis or Arrectocrinus abruptus.

ctena12a.jpg (19035 bytes) 3) One of the first things I saw were fragments of what appeared to be bone on the surface of the weathered limestone. Bone or vertebrate remains of any kind are rare here.  (Scale = cm) When I picked it up, I noticed that the fragments had a dentine-like coating on the surface.
ctena01a.jpg (10542 bytes) 4) I recovered all of the readily visible float on the surface and took it home to see if I could identify it. It appeared to be from a fairly rare shark called Ctenacanthus, known mostly from the two dorsal fin spines that are usually the only remains preserved. From the fragments that I had picked up, it appeared that I had found at least the bases of both dorsal fin spines. The fresh breaks seemed to indicate that further fragments might still be at the site. (Scale = mm)
ctena09a.jpg (12369 bytes) 5) Two days later we returned to site better equipped for digging and screening the weathered limestone. One of the first things I found was a bone-like fragment that was still in place in the weathered limestone.
ctena15a.jpg (7086 bytes) 6) After returning home, screening and cleaning the surface material, we found that we had most of the remaining fragments of the two dorsal fin spines and what appeared to be additional calcified cartilage (scapulo-coracoid and a fin ray).  Microscopic analysis located placoid scales from the shark. The two dorsal fin spines and the scapulo-coracoid are highlighted in red in the above drawing. (Scale = mm)
ctena23a.jpg (8621 bytes) 7) Another (left side) view of the anterior (left) and posterior (right) dorsal fin spines.  The anterior spine is about 25 cm long.   If this length is used to scale up the length of the fish from the above drawing, an estimated length of 1.6 m (5 ft) is obtained. (Scale = cm)
ctena07a.jpg (12143 bytes) 8) A cross section of the anterior dorsal fin spine. (Scale = mm)
ctena06a.jpg (13448 bytes) 9) The posterior margin of the near-distal portion of the anterior dorsal spine showing characteristic posterior denticles. (Scale = mm)
ctena19a.jpg (12372 bytes) 10) A posterior view of the anterior end of the posterior dorsal fin spine. (Scale = mm)
ctena24a.jpg (9861 bytes) 11) Another view of the 'teeth' (denticles) on the posterior side of the posterior dorsal fin spine. (Scale = mm)
ctena22a.jpg (14753 bytes) 12) A close-up of the ornamentation on the right side of the posterior dorsal fin spine. (Scale = mm)
ctena52a.jpg (10365 bytes) 13)  Detail of the ornamentation on the anterior end of the fin spine, near the insertion border.
ctena21a.jpg (12079 bytes) 14) The anterior edge of the posterior dorsal fin spine. (Scale = mm)
ctena18a.jpg (10389 bytes) 15) One of the scapulo-coracoids (pectoral girdle) of the shark. (Scale = mm).  Two cross sections of the fragment on the right are shown HERE
ctena17a.jpg (10972 bytes) 16) Four views of another unidentified piece of calcified cartilage - possibly a neural spine or a fin ray. (Scale = mm)
ctena16a.jpg (12376 bytes) 17) A fragment with a variety of calcified cartilage fragments and other structures, including placoid scales .... see micro-photographs below. (Scale = mm)
m-cten1a.jpg (6859 bytes) 18) A micro-photograph of a group of placoid scales, showing the smooth lower sides. Other views are  HERE and HERE. Approximate size of the group of scales in the lower left is 3 mm by 5 mm.  Each scale would be about 1 mm in length.
m-cten4a.jpg (6052 bytes) 19) A micro-photograph of another group of placoid scales showing the 'spines' on the upper surfaces. Other views are HERE and HERE
m-cten7a.jpg (6775 bytes) 20) A micro-photograph of the surface of the scapulo-coracoid.   The field of view in this picture is about 2 mm x 2 mm. The individual prisms of calcified cartilage are clearly visible. Another slightly different view is HERE.
21) First pictures (added 8/31/2002) of the right side of the nearly complete dorsal fin spines. (Scale = cm) ctena25a.jpg (13341 bytes)
22) Left and right views of the posterior dorsal fin spine. (Scale = cm) ctena29a.jpg (14075 bytes)
23) A posterior view of the tip of the posterior dorsal fin spine showing the posterior denticles. (Scale = mm) ctena28a.jpg (15756 bytes)
24) Recently recovered microscopic materials, including a broken tooth and a ganoid scale. A close-up photo of the broken placodont tooth is shown at far right.

ctena30a.jpg (9307 bytes)ctena31a.jpg (4316 bytes)

25) Another broken tooth. This tooth is very similar to the Cladodus occidentalis tooth described from Kansas by Joseph Leidy in 1859 and figured in by him in 1873. (See bottom of page)

ctena47a.jpg (17988 bytes)

26) On October 18, we revisited the site again to pick up additional samples of the matrix and to search again for additional remains that might still be in the ground.  As I looked around the surface of the site, I was pleased to find the remaining major piece of the anterior fin spine... sitting on top of a clump of small plants that had apparently sprouted under it. This fragment clearly shows the ornamentation that is present on both spines.

ctena33a.jpg (13350 bytes)

27) After we returned home, I fitted the new piece and several other, smaller fragments into the two fin spines.   The result is a nearly complete pair of dorsal fin spines, the anterior 37% longer than the posterior one (26 vs. 19 cm). Also shown is one of the scapulo-coracoids, a unidentified cartilaginous spine and a piece containing numerous cartilage fragments and scales. The specimen has been donated to the Sternberg Museum and is curated as FHSM VP-15012.

ctena32a.jpg (9569 bytes)

28) Further examination of the debris found in the matrix around the specimen turned up some interesting microfossils, including this perfectly preserved but tiny (1 mm) posterior  "Maiseyodus johnsoni" tooth (unpublished species name; Hansen, 1986). ID by Wayne Itano (9/2003).

Far right: Fig. 18, from Hansen (1986), used with permission.

pctena4a.jpg (9269 bytes) mh2teeta.jpg (12741 bytes)
29) These microfossils may be teeth of a small, and apparently rare, cladodont shark, identified as "Zangerlodus williamsi" (unpublished species name; Hansen, 1986). ID by Wayne Itano (9/2003). (Click HERE for larger pic)

Far right: Fig. 12, from Hansen (1986), used with permission (Scans courtesy of Wayne Itano)

pctena3a.jpg (10698 bytes) mh1teeta.jpg (11708 bytes)

Published figures and descriptions:

cope189a.jpg (15096 bytes)

Cope, E. D., 1892. Characters of Paleozoic fishes. Proc. U.S. Nat. Museum. 14:447-463, plate 23.  (Ctenacanthus amblyxiphias Cope 1891)

Vol. XIV, 1891]              PROCEEDINGS OF THE NATIONAL MUSEUM.                     449

                                       Ctenacanthus amblyxiphias, sp. nov. Fig.3. [Cope, E. D., 1891]

     Spine elongate, but little curved, moderately compressed; the posterior face with a flat median plane bounded by a shallow groove on each side. The ridges are wider than their interspaces, and they gradually become smaller posteriorly, so as to be half the diameter of the anterior ribs. The anterior border consists of a single rib of twice the diameter of. the largest lateral ribs. Its front surface is smooth; the sides are marked with shallow grooves directed downward, and the border is serrate with subacute tubercles, which point backward. The tubercles of the ribs are closely placed and vary from round to transverse in shape, and have a finely grooved surface. The line of the posterior hooks is flush with the sides of the spine. They are small, decurved, and subacute.

     The apex of the spine is wanting, so I call not give its length with certainty. It was probably about 10 1/2 inches. Measurements: Length of fragment, 190 millimeters; length of base presented (at front), 42 millimeters; diameters at middle, anteroposterior, 28 millimeters; transverse, 17 millimeters; transverse diameter of spine 140 millimeters, from base of fore surface 11 millimeters.

[From] The Permian formation of Texas; [Collected by] W. F. Cummins.

hussak1a.jpg (10884 bytes)

Hussakof, L., 1911. The Permian Fishes of North America, in Case, E. C., Revision of the Amphibia and Pisces of the Permian of North America.  Carnegie Institute of Washington. (Ctenacanthus amblyxiphias Cope 1891)

                                      Genus CTENACANTHUS Agassiz. [Hussakof, L. 1911]

         Poiss. Fos., III, 1837, p. 10.

    A provisional genus of sharks, to which are referred numerous paleozoic dorsal fin-spines, known to have had (at least in certain species referred to the genus) cladodont dentition and primitive fin-fold paired fins.

    Revised description of genus:

       1. Dorsal spines straight or gently arcuate, and more or less laterally compressed;  2. Lateral faces longitudinally ridged, the ridges smooth or ornamented with various types of denticulations or beading;    3. Posterior face flat or concave, usually with a series of small denticles along each margin.

    Ctenacanthus amblyxiphias Cope. (Plate 30, figs. 6-6a.)

    1891. Ctenacanthus amblyxiphias Cope, Proc. U. S. Nat. Mus., XIV, p. 449, pl. xxviii, fig. 3.

    1902. Ctenacanthus amblyxiphias Cope, Hay, Bull. U. S. Geol. Surv., No.179, p. 327.

Type: An imperfect spine. When complete about 25 or 30 cm. No.7283 Am. Mus. [from] Texas. Referred specimen: No.7282 (plate 30, fig. 6).

Original description: [See Cope -above]

romer42a.jpg (13707 bytes)  

Romer, A. S., 1942. Notes on certain American Paleozoic fishes. Amer. Jour.Sci., 240:216-228, 1 pl. 

                           CTENACANTHUS AMBLYXIPHIAS COPE. [Romer, A. S., 1942]

                                                (Plate 1, Figure 3).

"Spines of the Ctenacanthus type are common in Carboniferous deposits; their presence in the Texas redbeds is of interest as an upward extension of their stratigraphic range. One such Texas specimen was described by Cope (1891, p. 449, PI. 28, Fig. 3) as C. amblyxiphias, and Hussakof (1911, p. 161, Pl. 30, Figs. 6, 6a) described a second. In neither case was the locality or horizon given and data appears to be lacking on these specimens (AM 7283, 7282). A third fragmentary spine (AM 7263) is from the "Military Trail." The Harvard collections contain a number of Ctenacanthus spines or fragments of them, one of which is figured here. Most of them (MCZ Nos. 7199-8002) are from Little Bitter Creek (locality 1); another is from locality 5. In default of any worthwhile diagnostic characters we refer this material to Cope's species."

ke-005a.jpg (14182 bytes) Shown here are two large teeth of the cladodont shark, Cladodus occidentalis Leidy 1859, from the Lower Permian of Wabaunsee County, Kansas. (Click to enlarge).  See the ePaper (Leidy, 1859) here.

See Keith Ewell's Kansas shark discoveries here.

ke-013a.jpg (12962 bytes)

Other Ctenacanthus sites: Wayne Itano's discovery ------Dennis Murphy's site-------- The Earth History Portal


Chorn, J. and D.  Frailey, 1978. A large chondrichthyan spine, Physonemus mirabilis, from the Upper Pennsylvanian of Kansas, U.S.A. N. Jb. Geol. Paläont. Mh., (7):385-392, 1 fig.

Cope, E. D., 1891. Characters of Paleozoic fishes. Proc. U.S. Nat. Museum. 14:447-463. (Ctenacanthus amblyxiphias Cope 1891)

Everhart, M. J. and P. A. Everhart, 2003. First report of the Paleozoic shark, Ctenacanthus amblyxiphias Cope 1891 from the Lower Permian of Morris County Kansas. Kansas Acad. of Science (Abstracts), 22:13.

Hansen, Michael C., 1986, Microscopic chondrichthyan remains from Pennsylvanian marine rocks of Ohio and adjacent areas: unpublished Ph.D. dissertation, The Ohio State University, 535 p.

Hussakof, L., 1911. The Permian Fishes of North America, In Case, E. C., Revision of the Amphibia and Pisces of the Permian of North America.  Carnegie Institute of Washington. (Ctenacanthus amblyxiphias Cope 1891)

Itano, W. M., K. J. Houck and M. G. Lockley, 2003. Ctenacanthus and other chondrichthyan spines and denticles from the Minturn Formation (Pennsylvanian) of Colorado. Journ. Paleon. 77(3):524-535.

Leidy, J., 1859. [Xystracanthus, Cladodus and Petalodus from the Carboniferous of Kansas]. Proc. Acad. Nat. Sci. Phila., 11:3.

Maisey, J. G., 1975. The interrelationships of phalacanthous selachians. N. Jb. Geol. Paläont. Mh. 9:553-567, 6 fig.

Maisey, J. G., 1977. Structural notes on a cladoselachian dorsal spine. N. Jb. Geol. Paläont. Mh. 1:47-55, 6 fig.

Maisey, J. G., 1982. Studies on the Paleozoic selachian genus Ctenacanthus No. 2. Bythiacanthus St. John and Worthen, Amelacanthus St. John and Worthen, Sphenacanthus Agassiz, and Wodnika Münster. American Museum Noviates, 2722:1-24.

Maisey, J. G., 1984. Studies on the Paleozoic selachian genus Ctenacanthus Agassiz. No. 3.: Nominal species referred to Ctenacanthus. American Museum Noviates, 2774:1-20.

Mazzullo, S. J., C. S. Teal, and C. A. Burtnett, 1997. Outcrop stratigraphy and depositional facies of the Chase Group (Permian, Wolfcampian) in Kansas and southeastern Nebraska. Kansas Geological Survey Technical Series 6, 210 p.

Romer, A. S., 1942. Notes on certain American Paleozoic fishes. Amer. Jour. Sci., 240:216-228, 1 pl. 

St. John, O. A. and H. Worthen. 1875. Palæontology: Descriptions of fossil fishes. Geology and Palæontology, Part 2, Section 1, Geological Survey of Illinois, 6:245-532, i-vi, pl. 1-22.

Zangerl, R., 1981. Chondrichthyes I - Paleozoic Elasmobranchii. 3a:1-115 In Shultze, H-P. (ed.), Handbook of Paleoichthyology. Gustav Fischer Verlag, Stuttgart and New York.

Zidek, J., 1976. Oklahoma Paleoichthyology Part V: Chondrichthyes. Oklahoma Paleontology Notes, 36(5):175-192, Oklahoma Geol. Surv., Norman, OK.  

Acknowledgments:  A special "thank you" to Wayne Itano for the identification of the remains and a pre-publication copy of his new paper on Ctenacanthus in Colorado; to Larry Skelton of the Kansas Geologic Survey for the initial mapping and KGS road log information; to Dr. Salvadore Mazzullo (Wichita State University) for the stratigraphic information; to Earl Manning (Tulane University) for identification of the pectoral girdle and position of the two spines and the original calculations of the shark's length; and to Kenshu Shimada (DePaul University) and Bill May (Sam Noble Museum of Natural History) for providing copies of relevant reference materials.