Inarticulate Brachiopods are those that have calcium phosphate shells and open them with muscular articulation. Inarticulate brachiopods have a lophophore that has a centrally located oral opening through which food passes into stomach and an intestine that makes several loops that lead to an anus through which waste is ejected. Most inarticulates attach to the substrate with a long pedicle that protrudes from an opening in the beak of the brachiopod, but a few (Lingula) live in burrows and some (Crania) attach to some solid object, usually a productoid brachiopod.

Crania modesta

• Date Posted: 03/01/03
• Description: "Crania modesta" White and St. John. These examples of "Crania modesta" are unusual inasmuch as they are not attached to any other organism. In older rocks of late Pennsylvanian (Missourian) age, "C. modesta" is commonly attached to other invertebrates, by the time that the Hughes Creek Shale was deposited, "C. modesta" is found almost exclusively attached to the pedicle valves of the large productoid brachiopod, Reticulatia huecoensis (King).
• Database ID: 25

Orbiculoidea missouriensis

• Date Posted: 03/01/03
• Description: "Orbiculoidea missouriensis" (Shumard) is a coolie cap-shaped brachiopod that is commonly found in dark gray to black, fissile (platy) shale that probably represents deep, dysaerobic water and represents the point of maximum transgression of the seaway. Often the only macro-fossils that are contained in such shale are either "O. missouriensis" or "Lingula carbonaria". "O. missouriensis" has a slit-like pedicle opening.
• Database ID: 26

Lingula carbonaria

• Date Posted: 03/01/03
• Description: "Lingula carbonaria" Swallow is a tear-drop shaped inarticulate brachiopod that is common in black shale facies that represent deep, cold dysaerobic water. In addition to "Orbiculoidea missouriensis", "L. carbonaria" is found with microfossils called conodonts.
• Database ID: 27

Articulate Brachiopods are those that have calcium carbonate shells that open along a hinge line that usually has articulated teeth and sockets. In addition to differences in the shell composition and shell morphology, the articulate and inarticulate brachiopods have much different ontogenies (modes of growth). The pedicle of inarticulate brachiopods is a long, flexible tube that can be contracted or extended and which connects to the organs inside the brachiopod. The pedicle of articulate brachiopods is short and stout and does not connect to the organs inside the brachiopod. Although the pedicles of articulate and inarticulate brachiopods are not homologous, they are functionally equivalent (Rudwick, 1980). Some articulate brachiopods did not have pedicles and may have had an extended beak that pushed into the soft substrate to stabilize the animal and some had spines on their pedicle valves that attached to the substrate. The pedicle opening in some brachiopods is filled with tiny plates.

The lophophore of atrypoid brachiopods was supported by tiny spiral, spring-like structures that are called spiralia. Both atrypoid and spiriferoid brachiopods have spiralia, but atrypoids have very short hinge lines whereas spiriferoids have very long hinge lines.

Crurithyris planoconvexa

• Date Posted: 03/01/03
• Description: Two views of "Crurithyris planoconvexa" (Shumard) showing brachial valve (left) and two pedicle valves. "C. planoconvexa" is one species of brachiopod that is commonly found associated with bivalves. "C. planoconvexa" is commonly found in the offshore, dysaerobic environments where a diverse bivalve fauna is found, and it is usually the only species of brachiopod observed there. Rudwick (1965) has suggested that brachiopods with deeply plano-convex shells may have lived with convex shell pressed into the soft substrate. Mudge and Yochelson (1962) stated that the related species "C. expansa" (Dunbar & Condra) preferred argillaceous (clayey) environments, were commonly found in thin layers immediately above or unfossiliferous beds, and rarely carried any epifauna. Holterhoff and Pabian (1989) found "C. planoconvexa" to be the only species of brachiopod in the dysaerobic facies of the Hughes Creek Shale, a unit they mistakenly called the Bennett Shale.
• Database ID: 28

Composita subtilita

• Date Posted: 03/01/03
• Description: "Composita subtilita" (Hall), pedicle and brachial valves. "Composita subtilita" (Hall) is one of the most common brachiopods in the late Pennsylvanian and early Permian rocks of Nebraska. The genus "Composita" is difficult to separate into species and this problem was discussed by Mudge and Yochelson (1962) and Lutz-Garihan (1976). Dunbar and Condra (1932) based "C. subtilita" and "C. ovata" Mather on differences in juvenile brachiopods and stated that these differences merged in adults. Lutz-Garihan (1976) recognized two distinct morphotypes as end member of a gradational series and that the end members did not differ significantly and called these all intraspecific variants.
• Database ID: 29

Composita subtilita

• Date Posted: 03/01/03
• Description: "Composita subtilita" (Hall) showing spiralia on inside of pedicle valve. Spiralia, the coil-like lophophore supports, are rarely preserved in fossil brachiopods.
• Database ID: 30

Hustedia mormoni

• Date Posted: 03/01/03
• Description: "Hustedia mormoni" (Marcou) showing pedicle opening on large shell in center. The species "Hustedia mormoni" (Marcou) 1858 was one of the first invertebrate fossils described from what is now known as Nebraska. Marcou originally described this species as "Terebratula Mormoni" Marcou in his Geology of North America. Note that Marcou’s name appears outside of parentheses in the original description. When the species was moved to another genus, Hustedia, the species’ author’s name was placed in parentheses. This is a taxonomic practice. Marcou was a French Geologist who made the first bedrock map of what is now Nebraska. He was hired by Secretary of Interior, Jefferson Davis, who later became President of the Confederate States of America. Marcou left the United States at the outbreak of hostilities between the Confederacy and Union and eventually published his material from memory. His works proved to be quite accurate.
• Database ID: 31

Articulate brachiopods with inflated pedicle and brachial valves, well-developed teeth and sockets, long hinge lines, V-shaped pedicle openings without platelets, plicated or coarsely ribbed shells.

Neospirifer sp. cf. N. kansasensis

• Date Posted: 03/01/03
• Description: "Neospirifer" sp. cf. N. "kansasensis" (Swallow). Mudge and Yochelson (1962) assigned most of the Neospirifers from the Hughes Creek Shale in Kansas to N. dunbari R. E. King, and they based this on the number of plications in the fold of the pedicle valve. Dunbar and Condra (1932) stated that N. kansasensis had 18 to 20 plications in the fold on the pedicle valve. It is interesting that most of the Neospirifers in the Nebraska Geological Survey’s invertebrate paleontological collections, many of which were collected by Dunbar and Condra, carry the label Neospirifer kansasensis. The identification made by Dunbar and Condra is being retained here, but the large sample has never been systematically analyzed. Mudge and Yochelson (1962) pointed out that most specimens of N. dunbari were pedicle valves. A census of 283 specimens of N. kansasensis from about 20 different localities in Nebraska and Kansas revelaed 239 pedicle valves, 20 brachial valves, and 24 complete specimens. This brings to light a very important question: Where have all of the brachial valves gone? Were they selectively washed away by currents? Did some predator attack Neospirifer through the usually thinner brachial valve? Do the collections simply show collecting bias? Many questions can be brought to light by even a cursory examination of large samples.
• Database ID: 36

Strophomenoid Brachiopods are articulate brachiopods with usually flattened, semi-circular shells with a long hinge line and a V-shaped pedicle opening that is usually filled with tiny calcite plates.

Derbyia crassa

• Date Posted: 03/01/03
• Description: This example of "Derbyia crassa" (Meek and Hayden) was collected from the transgressive, deep, cold water, dysaerobic (oxygen deficient) facies of the lower Hughes Creek Shale in Richardson County. Note that it has a small thin, etched shell. Mudge and Yochelson (1962) stated that "Derbyia crassa" specimens that were collected from calcareous shale tended to be small. Diameter of large shell is about ¾ in (18 mm).
• Database ID: 37

Derbyia crassa

• Date Posted: 03/01/03
• Description: These are interior and exterior views of the pedicle valve of "Derbyia crassa" (Meek and Hayden). This example was collected from the regressive, shallow, warm water, aerobic (well-oxygenated) facies of the upper Hughes Creek Shale. Note that it has a thick, robust shell. Diameter of shell is about 2.0 in (50 mm). "D. crass" is characterized by having a rather flat shell comapred to all of the other species in this genus. Mudge and Yochelson (1962) also observed that "D. crassa" from Kansas usually carries no epifauna and the Nebraska specimens also bear this out.
• Database ID: 38

Chonetoid Brachiopods are articulate brachiopods with nearly flat shells with spines running the length of the hinge line.

Neochonetes granulifer

• Date Posted: 03/01/03
• Description: "Neochonetes granulifer" (Owen) is probably the most common brachiopod in the Hughes Creek Shale. In some outcrops, it may make up more than 50 percent of the macro-fauna. It is more common in the upper part of the Hughes Creek and replaces many of the large productoid and strophomenoid brachiopods that are more common in the lower parts of the Hughes Creek. Both Dunbar and Condra (1932) and Mudge and Yochelson (1962) recorded thick- and thin-shelled forms of this species. All from the Hughes Creek Shale in Nebraska studied here are thin-shelled forms. Thick-shelled forms have been found in the Florena Shale Member of the Beattie Formation in Nebraska.
• Database ID: 39

Neochonetes granulifer

• Date Posted: 03/01/03
• Description: "Neochonetes granulifer" (Owen) is probably the most common brachiopod in the Hughes Creek Shale. In some outcrops, it may make up more than 50 percent of the macro-fauna. It is more common in the upper part of the Hughes Creek and replaces many of the large productoid and strophomenoid brachiopods that are more common in the lower parts of the Hughes Creek. Both Dunbar and Condra (1932) and Mudge and Yochelson (1962) recorded thick- and thin-shelled forms of this species. All from the Hughes Creek Shale in Nebraska studied here are thin-shelled forms. Thick-shelled forms have been found in the Florena Shale Member of the Beattie Formation in Nebraska.
• Database ID: 40

Productoid Brachiopods are articulate brachiopods with highly inflated, spine bearing-pedicle valves, no pedicle opening, and long hinge lines. Some productoid brachiopods attached themselves to whatever solid substrate they could find by means of cementing spines to it. Others may have buried their concavo-convex pedicle valve in the soft substrate.

Hystriculina hystricula

• Date Posted: 03/01/03
• Description: "Hystriculina hystricula" (Dunbar & Condra) on "Thamniscus" sp. This is a splendid example of a productoid brachiopod "Hystriculina hystricula" (Dunbar & Condra) attached to a frond of ectoprocts. These examples are from the regressive facies of the Hughes Creek Shale.
• Database ID: 41

Hystriculina hystricula

• Date Posted: 03/01/03
• Description: "Hystriculina hystricula" (Dunbar & Condra) on "Thamniscus" sp. This is a splendid example of a productoid brachiopod "Hystriculina hystricula" (Dunbar & Condra) attached to a frond of ectoprocts. These examples are from the regressive facies of the Hughes Creek Shale.
• Database ID: 42

Hystriculina hystricula

• Date Posted: 03/01/03
• Description: Pedicle and brachial valves of "Hystriculina hystricula" (Dunbar & Condra); note the robust spine terminations on pedicle valve. These examples are from the regressive facies of the Hughes Creek Shale.
• Database ID: 43

Leptolosia ovalis

• Date Posted: 03/01/03
• Description: "Leptolosia ovalis" Dunbar and Condra is a very small species of productoid brachiopod. Further research may show that it is an immature example of previously described, larger species. Leptolosia is commonly found attached to other fossils. Specimens in the Nebraska Geological Survey collections show that "l. ovalis" is a long ranging species. It Is commonly attached to other productoid brachiopods. Pabian and Rushlau (2002) figured an example attached to a crinoid cup, and White and St. John (1867) and Dunbar and Condra (1932) have shown examples of other species of this genus attached to chaetetids and corals.
• Database ID: 44

Linoproductus magnispinus

• Date Posted: 03/01/03
• Description: "Linoproductus magnispinus" (Dunbar & Condra). The two shells show brachial and pedicle valves of "Linoproductus magnispinus" Dunbar & Condra. "L. magnispinus" is closely related to "L. prattenianus" (Norwood & Pratten); the former species has fewer, larger spines on the pedicle valve. Dunbar and Condra collected their type specimens of "L. magnispinus" from the Hughes Creek Shale in Lancaster and Nemaha counties. Dunbar and Condra (1932) also stated that in the horizon from which the types were collected, this species was so abundant that it formed shelly bands that extended from southeastern Nebraska to Oklahoma.
• Database ID: 45

Linoproductus magnispinus

• Date Posted: 03/01/03
• Description: "Linoproductus magnispinus" (Dunbar & Condra). The two shells show brachial and pedicle valves of "Linoproductus magnispinus" Dunbar & Condra. "L. magnispinus" is closely related to "L. prattenianus" (Norwood & Pratten); the former species has fewer, larger spines on the pedicle valve. Dunbar and Condra collected their type specimens of "L. magnispinus" from the Hughes Creek Shale in Lancaster and Nemaha counties. Dunbar and Condra (1932) also stated that in the horizon from which the types were collected, this species was so abundant that it formed shelly bands that extended from southeastern Nebraska to Oklahoma.
• Database ID: 46

Reticulatia huecoensis

• Date Posted: 03/01/03
• Description: "Reticulatia huecoensis" (R. E. King). This image shows the pedicle and brachial valves and the interior of a brachial valve of "Reticulatia huecoensis" (R. E. King). This species has been found in several outcrops of Hughes Creek Shale in southeastern Nebraska. This species originally described as "Productus huecoensis" R. E. King, 1931 and Dunbar and Condra described it as "Dictyoclostus americanus" in 1932. King’s name has priority and must be used. Muir-Wood and Cooper (1960) erected the genus "Reticulatia" to accommodate productoid brachiopods with a marked reticulation or net-like surface ornamentation and a long, half-round groove on the pedicle valve along which the brachial valve rotated.
• Database ID: 47

Reticulatia huecoensis

• Date Posted: 03/01/03
• Description: "Reticulatia huecoensis" (R. E. King). This image shows the pedicle and brachial valves and the interior of a brachial valve of "Reticulatia huecoensis" (R. E. King). This species has been found in several outcrops of Hughes Creek Shale in southeastern Nebraska. This species originally described as "Productus huecoensis" R. E. King, 1931 and Dunbar and Condra described it as "Dictyoclostus americanus" in 1932. King’s name has priority and must be used. Muir-Wood and Cooper (1960) erected the genus "Reticulatia" to accommodate productoid brachiopods with a marked reticulation or net-like surface ornamentation and a long, half-round groove on the pedicle valve along which the brachial valve rotated.
• Database ID: 48

Reticulatia huecoensis

• Date Posted: 03/01/03
• Description: "Reticulatia huecoensis" (R. E. King). This image shows the pedicle and brachial valves and the interior of a brachial valve of "Reticulatia huecoensis" (R. E. King). This species has been found in several outcrops of Hughes Creek Shale in southeastern Nebraska. This species originally described as "Productus huecoensis" R. E. King, 1931 and Dunbar and Condra described it as "Dictyoclostus americanus" in 1932. King’s name has priority and must be used. Muir-Wood and Cooper (1960) erected the genus "Reticulatia" to accommodate productoid brachiopods with a marked reticulation or net-like surface ornamentation and a long, half-round groove on the pedicle valve along which the brachial valve rotated.
• Database ID: 49

Orthoid Brachiopods are articulate brachiopods that have inflated valves, short hinge lines, and very small lophophore supports.

Rhipidomella carbonaria

• Date Posted: 03/01/03
• Description: "Rhipidomella carbonaria" (Swallow) is a very long-ranging species of brachiopod that has been found in rocks ranging in age from Desmoinesian (Middle Pennsylvanian) to Wolfcampian (Early Permian). This species is commonly found in the dark, silty shale facies of the offshore shale of a cyclothem.
• Database ID: 50

Rhipidomella carbonaria

• Date Posted: 03/01/03
• Description: "Rhipidomella carbonaria" (Swallow) is a very long-ranging species of brachiopod that has been found in rocks ranging in age from Desmoinesian (Middle Pennsylvanian) to Wolfcampian (Early Permian). This species is commonly found in the dark, silty shale facies of the offshore shale of a cyclothem.
• Database ID: 51

Rhynchonelloid Brachiopods are articulate brachiopods with small, wedge-shaped shells, sharply pointed beaks, and minute pedicle openings. They often have deep, plicated sinuses along the mid-section of the pedicle valve.

Wellerella osagensis

• Date Posted: 03/01/03
• Description: "Wellerella osagensis" (Swallow) seems to have preferred sedimentary environments that are now manifested as calcareous shale. "W. osagensis", however, is not abundant in any of the Hughes Creek Shale exposures we have examined.
• Database ID: 52