Atrypoid brachiopods are similar to spiriferoid brachiopods inasmuch as they also have spiralia. Atrypoid brachiopods, however, have short hinge lines and their shells may be either smooth or plicated.

Note on Composita: In their classic 1932 study "Brachiopoda of the Pennsylvanian System in Nebraska" Carl O. Dunbar and George E. Condra recorded at least four species of Composita from Nebraska. These are shown in the illustrations for your reference. Subsequent workers such as Norman Newell in Kansas and Myron Sturgeon and Richard Hoare in Ohio continued to recognize the species that were recognized or erected by Dunbar and Condra. Anne Lutz-Garihan studied a large number of Composita from the early Permian strata of Kansas and Oklahoma and showed that the genus was represented by an intergradational series of individuals that varied morphologically between two end members and none could be separated into groups that could be interpreted as separate species. Further, Lutz-Garihan showed that the end members did not differ in abundance and distribution in rock types, stratigraphic horizons or geographic areas and could not be explained as ecophenotypes, evolutionary populations or subspecies. Although Composita and its species have not been studied in the same detail as Lutz Garrihan's material, the genus shows a great variation in the Stull Shale of Nebraska, Iowa and Kansas.

Composita subtilita

• Date Posted: 09/11/02
• Description: "Composita subtilita" (Hall) is very common in the Kiewitz shale. The tiny white dots are made of a concentrically banded silica. This form of silica is often called "beekite" and it should not be confused with agate which formed in hollows or voids in the rock. Images by Ed Schafer; specimens from Bill Rushlau.
• Database ID: 177

Composita subtilita

• Date Posted: 09/11/02
• Description: "Composita subtilita" (Hall) is very common in the Kiewitz shale. The tiny white dots are made of a concentrically banded silica. This form of silica is often called "beekite" and it should not be confused with agate which formed in hollows or voids in the rock. Images by Ed Schafer; specimens from Bill Rushlau.
• Database ID: 178

Composita ovata

• Date Posted: 06/06/07
• Description: "Composita ovata" (Mather), 1915, ventral (left) and dorsal views
• Database ID: 256

Composita elongata

• Date Posted: 06/06/07
• Description: "Composita elongata" (Dunbar and Condra), 1932, ventral (left) and dorsal views
• Database ID: 257

Composita trilobata

• Date Posted: 06/06/07
• Description: "Composita trilobata" (Dunbar and Condra), 1932, dorsal (left) and ventral views
• Database ID: 258

Composita sp.

• Date Posted: 06/06/07
• Description: "Composita sp.", showing gradation from "C. elongata" to "C. ovata" to "C. trilobata"
• Database ID: 259

Spiriferoid brachiopods usually have long hinge lines and well-developed teeth and sockets. They have plicated or coarsely ribbed shells and probably attached to the substrate by a fleshy pedicle that protruded through a large, V-shaped pedicle opening. Their name is derived from a pair of internal structures called spiralia which are shaped like coil springs. The spiralia supported their food gathering mechanisms that in modern brachiopods resemble feathery tentacles.

Neospirifer triplicatus

• Date Posted: 09/11/02
• Description: "Neospirifer triplicatus" (Hall) is the dominant spiriferoid brachiopod in the Kiewitz Shale. Neospirifer may appear to be a fully grown "Punctospirifer" but the latter has punctae (tiny little holes) covering its valves. Image by Ed Schafer; specimens from Bill Rushlau.
• Database ID: 172

Neospirifer triplicatus

• Date Posted: 06/06/07
• Description: "Neospirifer triplicatus" (Hall), 1852 (above) and "N. triplicatus" var. "alatus" (Dunbar and Condra), 1932 (below)
• Database ID: 248

Neospirifer triplicatus

• Date Posted: 06/06/07
• Description: "Neospirifer triplicatus" (Hall), 1852
• Database ID: 249

Neospirifer sp. cf. N. latus

• Date Posted: 06/06/07
• Description: "Neospirifer sp. cf. N. latus" (Dunbar and Condra), 1932
• Database ID: 250

Neospirifer sp.

• Date Posted: 06/06/07
• Description: "Neospirifer sp." three shells showing gradation in morphology
• Database ID: 251

Punctospirifer kentuckyensis

• Date Posted: 06/06/07
• Description: "Punctospirifer kentuckyensis" (Shumard), 1852
• Database ID: 252

These brachiopods can become rather large, some having shells of 75 mm (3 inches) in diameter. Their pedicle opinings are usually filled with small calcite plates. Strophomenoid brachiopods probably remained immobile in the mud into which the extended their long, steeple-like beaks. The valves are commonly flattened toward the anterior and they have a circular outline with very fine costae. These brachiopods often have very well developed muscle scars on their interiors. Derbyia, Schuchertella and Streptorhynchus appear to be the most common genera of strophomenoid brachiopods in Nebraska.

Streptorhynchus affie

• Date Posted: 09/11/02
• Description: "Streptorhynchus affie" Girty appears to be a fairly short ranging species and most of the known examples have been collected from the Kiewitz shale along the lower Platte River valley. Its' elongated beak may have simply been pushed into the substrate to anchor the shell. Image by Ed Schafer; specimens from Bill Rushlau.
• Database ID: 173

Derbyia crassa

• Date Posted: 09/11/02
• Description: "Derbyia crassa" (Meek & Hayden) is fairly common in the deposits of the Missouri series of the late Pennsylvanian that are exposed along the lower Platte River valley. This species was one of the first to be named by pioneer geologists F. B. Meek and F. V. Hayden in 1858 in Nebraska. Image by Ed Schafer; specimens from Bill Rushlau.
• Database ID: 174

Chonetoid brachiopods are typified by having nearly semi-circular shells with flat to only slightly inflated brachial and pedicle valves. They have spines along the hinge line of the pedicle valve and the pedicle opening is closed up with tiny plates. Chonetoid brachiopods appear to be most common in fairly muddy water environments. They may have fixed themselves to the substrate by sinking their spines in the muddy bottom. There are a number of genera of chonetoid brachiopods with the suffix "---chonetes" which should be pronounced "cone eat ease".

Neochonetes granulifer

• Date Posted: 09/11/02
• Description: "Neochonetes granulifer" (Owen) is the species on which Robert Lindsay based a "Neochonetes" community that is based on the abundance of these brachiopod in the Kiewitz shale. Neochonetes granulifer specimens have half round, flat shells whose brachial valves have small spines along the hinge line. Image by Ed Schafer; specimens from Bill Rushlau.
• Database ID: 176

Neochonetes granulifer

• Date Posted: 06/06/07
• Description: "Neochonetes granulifer" (Owen), 1852, dorsal (above) and ventral views. Note worm tube attached to example in upper left corner.
• Database ID: 254

Chonetinella verneuiliana

• Date Posted: 06/06/07
• Description: "Chonetinella verneuiliana" (Norwood and Pratten), 1855, ventral (above) and dorsal views (below)
• Database ID: 255

Productoid brachiopods are characterized by having highly inflated, and spinose pedicle valves, long hinge lines, and large beaks. The spines may be several inches long. Some genera such as Antiquatonia have but a few robust spines whereas others such as Pulchratia have numerous, fine spines. Some productoid brachiopods probably settled into a soft substrate by imbedding their spines in the soft substrate whereas some productoids appear to have cemented their spines to a hard object in the substrate. There are several distinct species of productoids in the Pennsylvanian of the mid-continent. Growth series have generally not been constructed for many of these brachiopods so it is not known which "species" are valid and which are growth stages of a described species.

Antiquatonia portlockianus

• Date Posted: 09/11/02
• Description: "Antiquatonia portlockianus" has been observed in both nearshore and offshore environments. This species commonly reaches 35 mm to 40 mm measured along the hinge line. Image by Ed Schafer; specimens from Bill Rushlau.
• Database ID: 165

Echinaria moorei

• Date Posted: 09/11/02
• Description: "Echinaria moorei" (Dunbar & Condra) is very similar to "Pulchratia symmetrica" (McChesney). Both species tend to be found in similar environments and subsequent research may show that they are synonyms of one another. Very small specimens of neither species have been collected in large numbers to date and the systematics of these species may never be understood until growth series of these fossils can be made. Images by Ed Schafer; specimens from Bill Rushlau.
• Database ID: 166

Echinaria moorei

• Date Posted: 09/11/02
• Description: "Echinaria moorei" (Dunbar & Condra) is very similar to "Pulchratia symmetrica" (McChesney). Both species tend to be found in similar environments and subsequent research may show that they are synonyms of one another. Very small specimens of neither species have been collected in large numbers to date and the systematics of these species may never be understood until growth series of these fossils can be made. Images by Ed Schafer; specimens from Bill Rushlau.
• Database ID: 167

Reticulatia huecoensis

• Date Posted: 09/11/02
• Description: "Reticulatia huecoensis" (King) was named in 1931 and it has a year's priority over the name Dictyoclostus americanus Dunbar and Condra 1932 which was used in their classic volume. When the same species has two different names, the name first used name has priority over all others regardless of quality, condition or any other feature of the fossil. Such names are called synonyms. Image by Ed Schafer; specimens from Bill Rushlau.
• Database ID: 169

Pulchratia symmetricus

• Date Posted: 09/11/02
• Description: "Pulchratia symmetricus" (McChesney) seems to have been very much at home in the seas and on the substrate that covered eastern Nebraska when the sediments that formed the Kiewitz shale were deposited. This species has a very short stratigraphic range and most of the known specimens have been collected from the Kiewitz shale. The generic name Pulchratia was derived from the Latin root word for beautiful and was first applied by Helen Muir-Wood and Gus Cooper in their classic volume on productoid brachiopods. Images by Ed Schafer; specimens from Bill Rushlau.
• Database ID: 170

Pulchratia symmetricus

• Date Posted: 09/11/02
• Description: "Pulchratia symmetricus" (McChesney) seems to have been very much at home in the seas and on the substrate that covered eastern Nebraska when the sediments that formed the Kiewitz shale were deposited. This species has a very short stratigraphic range and most of the known specimens have been collected from the Kiewitz shale. The generic name Pulchratia was derived from the Latin root word for beautiful and was first applied by Helen Muir-Wood and Gus Cooper in their classic volume on productoid brachiopods. Images by Ed Schafer; specimens from Bill Rushlau.
• Database ID: 171

Antiquatonia portlockianus

• Date Posted: 06/06/07
• Description: "Antiquatonia portlockianus" var. "crassiocostatus" (Dunbar and Condra), 1932
• Database ID: 233

Cancrinella boonensis

• Date Posted: 06/06/07
• Description: "Cancrinella boonensis" (Swallow) 1856-60, pedicle valves
• Database ID: 234

Hystriculina wabashensis

• Date Posted: 06/06/07
• Description: "Hystriculina wabashensis" (Norwood & Pratten), 1854, three ventral and one dorsal view
• Database ID: 235

Juresania nebrascensis

• Date Posted: 06/06/07
• Description: "Juresania nebrascensis" (Owen), 1852, pedicle valves
• Database ID: 236

Leptalosia ovalis

• Date Posted: 06/06/07
• Description: "Leptalosia ovalis" (Dunbar and Condra), 1932, two pedicle valves attached to crinoid stem by long spines.
• Database ID: 237

Linoproductus prattenianus

• Date Posted: 06/06/07
• Description: "Linoproductus prattenianus" (Norwood & Pratten), 1854, pedicle valves showing two growth stages.
• Database ID: 238

Planispina armata

• Date Posted: 06/06/07
• Description: "Planispina armata" (Girty), 1908, attached to "Composita trilobata?"
• Database ID: 239

Planispina armata

• Date Posted: 06/06/07
• Description: "Planispina armata" (Girty), 1908, brachial valve.
• Database ID: 240

Planispina armata

• Date Posted: 06/06/07
• Description: "Planispina armata" (Girty), 1908, brachial valves
• Database ID: 241

Planispina armata

• Date Posted: 06/06/07
• Description: "Planispina armata" (Girty), 1908, on "Antiquatonia sp."
• Database ID: 242

Planispina armata

• Date Posted: 06/06/07
• Description: "Planispina armata" (Girty), 1908, on "Antiquatonia sp."
• Database ID: 243

Planispina armata

• Date Posted: 06/06/07
• Description: "Planispina armata" (Girty), 1908, on "Antiquatonia sp."
• Database ID: 244

Pulchratia ovalis

• Date Posted: 06/06/07
• Description: "Pulchratia ovalis" (Dunbar and Condra), 1932, dorsal view.
• Database ID: 245

Pulchratia ovalis

• Date Posted: 06/06/07
• Description: "Pulchratia ovalis" (Dunbar and Condra), 1932, ventral view.
• Database ID: 246

Reticulatia huecoensis

• Date Posted: 06/06/07
• Description: "Reticulatia huecoensis" (R.E. King), 1931, pedicle valve
• Database ID: 247

These are characterized by having ovate, smooth shells with pedicle openings. See the examples of recent brachiopods from New Zealand. Most extant brachiopods are terebratuloids, which appear to be closely related to such forms as the atrypoid brachipods such as Composita. Such is not the case. The former has its food gathering system supported by a large, single loop inside the shell whereas the latter has it food gathering system supported by spiralia.

There are no items in the collection.