DOI: 10.15468/qscmex
title: The lower actinopterygian fauna from the Lower Carboniferous Albert shale formation of New Brunswick, Canada - a review of previously described taxa and a description of a new genus and species

description: This dataset contains the digitized treatments in Plazi based on the original journal article Mickle, Kathryn E. (2017): The lower actinopterygian fauna from the Lower Carboniferous Albert shale formation of New Brunswick, Canada - a review of previously described taxa and a description of a new genus and species. Fossil Record 20 (1): 47-67, DOI: 10.5194/fr-20-47-2017, URL: http://dx.doi.org/10.5194/fr-20-47-2017Abstract. The Lower Carboniferous Albert shale formation of New Brunswick, Canada, is well-known for the preservation of countless articulated lower actinopterygian palaeoniscoid fishes. This site is at the boundary between the Devonian and the Lower Carboniferous, making the lower actinopterygians preserved at this site important. The taxonomic history of previously described Albert shale formation actinopterygians is reviewed here. Many of the earliest described actinopterygian taxa from the Albert Formation are represented by poorly preserved type specimens and have the distinction of being moved from one paraphyletic genus to another paraphyletic genus. While these taxa are in need of major redescriptions, such work is premature until the large paraphyletic or polyphyletic genera they have been placed in, Palaeonicus[m], † Rhadinichthys, and † Elonichthys, are redescribed. But there is new diversity within the Albert shale formation. Here, a new lower actinopterygian species, † Lambeia pectinatus, is described from one well-preserved specimen. This new species is characterized by dorsal ridge scales with pectinated posterior margins, body scales inserted between adjacent dorsal ridge scales, body scales with pectinated posterior and ventral margins, the presence of a ventral rostro-premaxilla and a median rostral bone, a separate and distinct antorbital bone, and a single supraorbital bone. This newly described species is distinct from previously described fishes from the Albert Formation, and the morphology of this newly described species is more similar to later Carboniferous fishes rather than Devonian fishes. This suggests that morphological features commonly seen in Carboniferous fishes and rarely seen in Devonian fishes were present early in the Carboniferous.1 Introduction1.1 The Albert shale formationFor over 150 years, lower actinopterygian, or palaeoniscoid, fishes have been described from the Albert shales of southeastern New Brunswick, Canada (Fig. 1). The term Albert shales has been used informally to refer to the Albert shale formation, the middle formation of the Horton Group between the basal Memramcook Formation and the overlying Weldon Formation (Gussow, 1953; Greiner, 1962) (Fig. 2). Greiner (1962) and Utting (1987) present the Albert Formation itself as being composed of three members – the Dawson Settlement, Frederick Brook, and Hiram Brook members (Fig. 2). St. Peter (1993) presents the Albert Formation as being composed of six stacked lithofacies – conglomerate, sandstone, mudstone, mudstone/sandstone, kerogenous mudstone, and evaporate facies.Since the 1800s, there has been controversy over the age of the Albert Formation. While an Early Carboniferous age was supported by the fossil fish and plants (Bailey and Ells, 1878; Lambe, 1909, 1910), some cautioned that the Albert Formation could be Devonian in age (Bailey et al., 1880; Ells, 1903). This trend continued into the late 1900s. Greiner (1962, 1974) had originally described the Albert Formation as Lower Carboniferous in age, but after the description of an osteolepid, † Latvius porosus from basal beds, he considered the lower part of the Albert Formation to be Devonian (Greiner, 1977). Recent reassessments of the Albert Formation sarcopterygian material do not support Greiner’s assignment of the material to the Devonian genus † Latvius, but rather suggest megalichthyid and Carboniferous affinities (Miller and Brazeau, 2007). This, combined with spore analyses, has put an end to the controversy regarding the age of the Albert Formation. The Albert Formation is Tournaisian (Lower Carboniferous) in age, near the Devonian and Lower Carboniferous boundary (Utting, 1987; St. Peter, 1993; Miller and Brazeau, 2007).Figure 2. Stratigraphic column of the Lower Carboniferous of New Brunswick, Canada. Figure modified after Utting (1987, fig. 2).Figure 1. Map of locality. (a) Map of North America; box highlights area enlarged in (b). (b) Close up of New Brunswick, Canada. Dashed line indicates Albert County, where the majority of the specimens were collected. Black dot indicates Hillsborough, the site at which the original material described by Jackson was collected. Scale bar equals 50 km; (a) not to scale. Map modified from Google Maps, Map Data: ' 2015 Google.The Albert Formation is paleontologically famous for its countless articulated lower actinopterygian specimens (Greiner, 1977). These actinopterygians are important because with the supported Early Carboniferous age of the Albert Formation, they potentially bridge morphological gaps between Devonian and Carboniferous forms. Unfortunately, these fishes have not been dealt with in great detail for over a hundred years. The taxonomic history of the Albert Formation fishes is discussed here.1.2 Review of the taxonomic history of the Albert Formation palaeoniscoidsThe palaeoniscoid fishes from the Albert Formation of New Brunswick have been a taxonomic nightmare for over 150 years. Lambe (1909, 1910) provided a taxonomic history of these fishes in his redescription of some of the New Brunswick fishes. This information is reviewed and updated below.In 1851, Jackson described the first palaeoniscoid fishes from the Albert shales in papers entitled “Report on the Albert Coal Mine” (Jackson, 1851a) and “Descriptions of five new species of fossil fishes” (Jackson, 1851b). Though the second title claims to include the descriptions of five new taxa, only three new species were described and named – † Palaeoniscus [m] alberti, † P. brownii, and † P. cairnsii. Four additional specimens were described but never named. No type material was designated, and though plates and figures are referenced in this publication, they were never included with the text (Lambe, 1909, 1910).Eastman (1908) and Lambe (1910) concluded that though Jackson’s plates and figures were never published with the original descriptions, a few must have existed and been distributed to paleontologists because the plates were referenced by other scientists (see Traquair, 1877, p. 49; Dawson, 1877, p. 338). Dawson (1877) described two new palaeoniscoid species from the Albert Formation – † Palaeoniscus [m] modulus and † Palaeoniscus [m] jacksonii. Again, no type material was designated. Dawson (1877) also provided additional comments on Jackson’s original species and referenced particular specimens figured by Jackson (1851a, b).In the late 1800s and early 1900s, many scientists commented on how the Albert Formation palaeoniscoids were more similar to species within the genera † Rhadinichthys and † Elonichthys. As detailed by Lambe (1910), Traquair (1877) commented that † Palaeoniscus [m] alberti and † P. cairnsii are closely allied to † Rhadinichthys carinatus (Agassiz). This reassignment was later upheld by Traquair (1911). Traquair (1877) referred † Palaeoniscus [m] brownii to † Elonichthys brownii. Newberry (1899) upheld Traquair’s (1877) reassignments. In Woodward’s catalogue (1891), † Palaeoniscus [m] alberti, † P. cairnsii, and † P. modulus were referred to † Rhadinichthys alberti, † R. cairnsii, and † R. jacksoni (1891). Woodward (1891) also assigned † Palaeoniscus [m] brownii to † Elonichthys brownii, but also noted that he felt this was a “doubtful” and illdefined species (Lambe, 1910). Eastman (1908) also referred the New Brunswick species to the genera † Rhadinichthys and † Elonichthys. In the same publication, Eastman described a new species from the Albert shales – † Elonichthys elegantulus – but no type specimen was designated (1908). All of the reassignments by Traquair (1877), Newberry (1889), Woodward (1891), and Eastman (1908) were done without justifications for these reidentifications.Sometime before 1908, Jackson’s original unpublished plates were discovered by Eastman in the Yale Peabody Museum (Eastman, 1908; Lambe, 1910). Using these plates, it was possible for Lambe (1909, 1910) to identify some of Jackson’s original type and figured specimens in the collections of the Museum of Comparative Zoology, Harvard, and the Boston Society of Natural History. Using this new information, Lambe (1909, 1910) was able to redescribe the Albert Formation fishes and describe a new taxon, † Elonichthys ellsi. Agreeing with Traquair (1877, 1911), Woodward (1891), and Newberry (1908), Lambe (1909, 1910) referred † Palaeoniscum alberti to † Rhadinichthys alberti and † P. brownii to † Elonichthys brownii. Lambe (1909, 1910) also determined that † Palaeoniscum cairnsii (Jackson, 1851a, b) was not a valid species, nor was † Elonichthys († Palaeoniscum) jacksoni (Dawson, 1877). Lambe (1909, 1910) also referred † Palaeoniscum modulus (Dawson, 1877) to † Canobius modulus, and the validity of † Elonichthys elegantulus (Eastman, 1908) was called into question.Reassignments of Albert shale fishes continued in the later 1900s. Moy-Thomas (1938) commented that Westoll considered † Canobius modulus to be † R. alberti and agreed with Westoll that † C. modulus is synonymous with † R. alberti. Sternberg (1939) studied newly collected specimens from the Albert Formation and assigned these specimens to † R. alberti. Sternberg (1939) cautioned though that there were differences in measurements and ratios between the specimens designated as † R. alberti, suggesting that there is more than one species within this taxon or that the species is characterized by a great degree of variation. Gardiner commented on the Albert Formation fishes in his catalog of Canadian fossil fishes (Gardiner, 1966). Miller and McGovern (1996) published a preliminary report describing palaeoniscoids tentatively identified as † Elonichthys from the Albert shales in Norton, New Brunswick, Canada. This has been the last work that has investigated the actinopterygian fauna of the Albert shale formation until this current work.Jackson’s original taxa – † Rhadinichthys alberti, † R. cairnsii, and † Elonichthys brownii – are discussed here. Some of these specimens have a long history of moving from one museum collection to another and have changed catalog numbers over the years. This makes identifying specimens mentioned in older literature difficult. Tables 1 and 2 detail the numerous identities of the original Jackson and Lambe specimens, respectively. Two questionable taxa from the Albert Formation – † Rhadinichthys elegantulus (Gardiner, 1966, states that the type is in the Museum of Comparative Zoology, Harvard (MCZ); no number given) and † Canobius modulus (Gardiner, 1966, states that the type is in Redpath Museum, McGill University; no number given) have never had type specimens designated. The statuses of these taxa are examined here as well.1.3 Problem of generic assignment of the Albert Formation palaeoniscoidsThe majority of the actinopterygians described from the Albert Formation have been placed within the poorly defined and paraphyletic genera † Palaeoniscum, † Elonichthys, or † Rhadinichthys. This problem is intensified by the fact that the type specimens of some of these genera are poorly preserved and uninformative. The specific problems with these genera are described below, as well as suggestions on how to deal with these problems.1.3.1 † PalaeoniscumOriginally described in 1818 by Ducrotay de Blainville, the genus † Palaeoniscum has been a problematic one. After Ducrotay de Blainville’s original description, Agassiz (1833) found no distinction between † Palaeoniscum and another genus described by Ducrotay de Blainville, † Paleothrissum. Agassiz (1833) combined the two genera into a new genus, † Palaeoniscus, keeping the same type species as Ducrotay de Blainville (1818). Jordan (1917) regarded Agassiz’s use of the term † Palaeoniscus as a misspelling and called for the use of the name † Palaeoniscum and authority going to Ducrotay de Blainville (1818). It should be noted that Ducrotay de Blainville’s original specific epithet was † Palaeoniscum freieslebenense (Ducrotay de Blainville, 1818), not the spelling that is used today, † Palaeoniscum freieslebeni.Troschel (1857) recognized that Agassiz’s † Palaeoniscus [m] could probably be divided into two different genera based on scale morphologies. After Agassiz, many species of † Palaeoniscus [m] were described, though as Traquair (1877) pointed out, many of these species are dubious.Table 1. Identities of Jackson’s figured specimens. Plate and figure numbers, past and present museum catalog numbers, Jackson’s (1851a, b) and Lambe’s (1910) identifications, and type status included. Abbreviations: BSNH, Boston Society of Natural History; MCZ, Museum of Comparative Zoology. Genera abbreviated: E., Elonichthys; P., Palaeoniscum; R., Rhadinichthys.Plate and fig. no. BSNH Former Current Jackson (1851) Lambe (1910) Type Jackson (1851a, b) no. MCZ no. MCZ no. ID ID status Plate I, fig. 1 7899 1960 5082 † P. alberti † R. alberti Holotype Plate I, fig. 2 7900 1961 5083 † P. brownii † E. brownii Holotype Plate I, fig. 3 7899a 1956 5084 † P. cairnsii † R. alberti Holotype † P. cairnsii (Jackson) Plate I, fig. 4 Lost? X X † Palaeoniscus sp. † E. brownii Holotype † P. jacksoni (Dawson) Plate I, fig. 5 7901 1957 5085 Not mentioned † E. brownii Plesiotype Plate II, fig. 1 7902 6150 † Palaeoniscus sp. † E. brownii Plate II, fig. 2, 2 bis 7987 1959 5086 † Palaeoniscus sp. † R. alberti Plate II, fig. 3 7987a 1958 5087 † Palaeoniscus sp. † R. alberti Plate II, fig. 4 Lost? X X Not mentioned X Plate II, fig. 5 7898 6151 Not mentioned † R. alberti Plate II, fig. 6 Lost X X X X Plate II, fig. 7 7903 1953 5088 † Palaeoniscus sp. Plate II, fig. 8 7898a 6152 Not mentioned † R. albertiTable 2. Identities of Lambe’s (1910) figured specimens. Plate and figure numbers, past and present museum catalog numbers, and identifications included when known. Abbreviations: BSNH, Boston Society of Natural History; MCZ, Museum of Comparative Zoology. Genera abbreviated: E., † Elonichthys; R., † Rhadinichthys.Plate and fig. no. Original Former Current Current Lambe (1910) Lambe (1910) BSNH no. MCZ no. MCZ no. CMN no. ID Plate III, fig. 1? ? ? ? † R. alberti Plate III, fig. 2? ? ? ? † R. alberti Plate III, fig. 3? ? ? ? † R. alberti Plate III, fig. 4 7899a 1956 5084 X † R. alberti Plate III, fig. 5 7987a 1958 5087 X † R. alberti Plate III, fig. 6 7987a 1958 5087 X † R. alberti Plate IV, fig. 1 7900 1961 5083 X † E. brownii Plate IV, fig. 2 7900 1961 5083 X † E. brownii Plate IV, fig. 3 7902 6150 X † E. brownii Plate IV, fig. 4 7901 1957 5085 X † E. brownii Plate V, fig. 2, 3, 5, 6 7900 1961 5083 X † E. brownii Plate V, fig. 4 7902 6150 X † E. brownii Plate VI, fig. 1? ? ? ? † E. brownii Plate VII, fig. 1? ? ? ? † E. brownii Plate VIII, fig. 1? ? X 4384 † E. brownii Plate IX, fig. 1? ? ? ? † E. browniiTraquair (1877) recognized the problem with the genus † Palaeoniscus [m] early on and concluded that the genus † Palaeoniscus [m] was composed of a large number of species that were referable to more than one genus. Traquair (1877) further commented that it seemed that any small fusiform, rhombic-scaled actinopterygian from Paleozoic rocks seemed to be placed in this genus without comparison with the original type specimen. Traquair attempted to remedy the problem by restricting the species included in this genus to † Palaeoniscum freieslebeni, † P. magnus, † P. macropomus, † P. elegans, † P. comptus, † P. longissimus, and † P. macrophthalmus (Traquair, 1877).Though a step towards constraining and defining just what constitutes † Palaeoniscum, Traquair’s (1877) diagnosis is problematic in that it provides a list of characteristics that are not diagnostic, not even when taken as a unit. The diagnosis of † Palaeoniscum includes characters common to Paleozoic actinopterygians such as a fusiform body, jointed fin rays in the pectoral fin, small fulcra on the pectoral fin, the dorsal fin originates anterior to the anal fin, oblique suspensorium, and small conical teeth (Traquair, 1877). Even with restricting which species are included within † Palaeoniscum, the genus is still in need of redescription. Woodward (1891) followed Traquair (1877) by restricting which species were included in the genus † Palaeoniscum. While Traquair recognized the problem with † Palaeoniscum early, his conclusions reviewed above still describe the situation today. A conservative approach would be to restrict † Palaeoniscum to † P. freieslebeni and to reinvestigate and redescribe the other species placed within this genus.1.3.2 † RhadinichthysThe genus † Rhadinichthys was erected by Traquair (1877) to house species that were once considered to belong to the genus † Palaeoniscum. The type species of † Rhadinichthys, † R. ornatissimus, was originally described as a species of † Palaeoniscus [m] by Agassiz (1835). Traquair’s original 1877 diagnosis of † Rhadinichthys includes characteristics such as a slender body, very oblique suspensorium, a dorsal fin originating almost opposite the anal fin, and the principal rays of the pectoral fin being unarticulated until close to their terminations. Again, these characters are not diagnostic and quite general among lower actinopterygians.After describing four species of † Rhadinichthys from the Carboniferous of Glencartholm, Moy-Thomas and Bradley Dyne (1938) remarked that the genus could be divided into two different types – one with long thin bodies and small fins and the other with deeply fusiform bodies with large fins. They concluded that † Rhadinichthys “requires complete revision” and that the forms that they discussed would be more accurately described after revisionary work was done (Moy-Thomas and Dyne, 1938, p. 457). Romer (1945) erected a family, the Rhadinichthyidae, for which † Rhadinichthys is the type genus. This work was done without the reinvestigation of the genus called for by Moy-Thomas and Bradley Dyne (1938).Gardiner and Schaeffer (1989) attempted to divide lower actinopterygians into different generic groups. Different † Rhadinichthys species were placed in different generic groups. When this was done, Gardiner and Schaeffer (1989) followed the convention of Wiley (1981) and placed the genus name in shutter quotes to signify its paraphyletic state. For example, “† Rhadinichthys ” canobiensis is placed in the † Australichthys group, whereas “† Rhadinichthys ” carinatus is placed within the † Belichthys group and the type species of † Rhadinichthys, † R. ornatissimus, is placed within the † Amblypterus group (Gardiner and Schaeffer, 1989).Lund and Poplin (1997) reappraised the Rhadinichthyidae and the genus which gives this family its name, primarily based on newly described Bear Gulch fishes they placed within the Rhadinichthyidae. They recognized the following features as diagnostic of Rhadinichthyidae: a prominent snout and subterminal mouth; two suborbital bones; operculum higher but narrower than suboperculum; a triangular dorsal fin with an origin almost equal to that of the anal fin; a deeply cleft and inequilobate caudal fin, fin rays distally bifurcated in all fins; a reverse L-shaped “antorbital” bone; rostropostrostral not contributing to the rim of the mouth, no premaxillae; absence of premaxillae results in a rostral notch below the rostropostrostral and between the antorbitals; no supraorbital bones; an anamestic anocleithrum; elongated clavicles; and low ventrolateral abdominal scale rows (Lund and Poplin, 1997). While this was a step in the right direction, the redescription of † Rhadinichthys, the type genus of the family Rhadinichthyidae, had not been done prior to Lund and Poplin’s (1997) redescription of the Rhadinichthyidae. † Rhadinichthys should be viewed as a paraphyletic genus and should be the focus of future revisionary work.1.3.3 † ElonichthysThe genus † Elonichthys was described by Giebel (1848). The type species of † Elonichthys, † E. germari, is represented by a poor type specimen (Schultze and Bardack, 1987; Malabarba, 1988; Long, 1988; Schindler, 1993). As pointed out by Schultze and Bardack (1987), the type specimen of † Elonichthys germari does not allow for confirmation of generic designation. Malabarba (1988) also commented on the poor quality of the type species of this genus and our poor understanding of the genus as a whole. Schindler (1993) described † Elonichthys as being a “summary” genus that cannot be clearly defined.Schultze and Bardack (1987) and Malabarba (1988) have both discussed the paraphyletic/polyphyletic nature of the genus † Elonichthys. Long (1988, p. 39) cautioned that many Carboniferous species of † Elonichthys have been erected on characters of “dubious phylogenetic value” and that the genus could be paraphyletic. Long (1988) also identified a further problem with this genus, primarily that many of the specimens assigned to this genus are too poorly preserved.Gardiner and Schaeffer (1989) placed various species of † Elonichthys in different groups and have shutter quotes around the genus name, suggesting they also thought that the genus was paraphyletic. Recognizing the problems with this genus, Schindler (1993) avoided phylogenetic discussion of † Elonichthys and also placed the name in shutter quotes. A further problem with this genus is the fact that according to Malabarba (1988) and Gardiner (cited as personal communication in Malabarba, 1988) † Elonichthys serratus is more similar to † Palaeoniscum freieslebeni than to † Elonichthys germari.More recently, progress has been made regarding Elonichthys. Poschmann and Schindler (2004) revised the family Elonicthyidae. Schindler (2009) concluded that all specimens recovered from the type locality of Elonichthys germari belong to E. germari. These newly found specimens include disarticulated remains, scales, as well as partially articulated remains (Schindler, 2009). These specimens, as well as the original type material, are the basis of an ongoing revision of the genus Elonichthys that will be published soon (Schindler, 1993; Schindler, personal communication, 15 November 2016).Overall, † Palaeoniscum, † Rhadinichthys, and † Elonichthys represent paraphyletic genera that are in need of revision. This revisionary work is beyond the scope of this study. Recognizing the problems with these genera, and the high likelihood that revisionary work may lead to the erection of multiple new genera, it has been decided to not place any new species from the Albert Formation or elsewhere within these genera. Species cannot be confidently assigned to these taxa because it is unclear what defines these genera to begin with. This also hinders redescriptions of the New Brunswick fishes, which have been moved from one poorly understood genus to another.1.4 Previous descriptions of Albert Formation palaeoniscoidsOverall, the original taxa described from the Albert Formation are represented by poorly preserved type specimens, undiagnostic descriptions, and reassignments from one paraphyletic genus to another paraphyletic genus. These difficulties are reviewed below for † Rhadinichthys alberti, † Rhadinichthys cairnsii, † Elonichthys ellsi, † Elonichthys († Rhadinichthys) elegantulus, and † Canobius modulus.Figure 3. Illustrations of type specimens of Jackson’s (1851) original species from the Albert Formation of New Brunswick, Canada. (a) † Rhadinichthys († Palaeoniscum) alberti, illustration of MCZ 5082; (b) † Rhadinichthys († Palaeoniscum) cairnsii, illustration of MCZ 5084; (c) † Elonichthys brownii, illustration of MCZ 5083. Dashed lines represent areas of ambiguity that have been reconstructed. Scale bars equal 5 mm.1.4.1 † Rhadinichthys albertiJackson’s original description of † Palaeoniscum alberti is based on the specimen depicted in plate I, fig. 1 (Jackson, 1851a, b). This specimen was later identified as BSNH 7899, which was changed to catalog number MCZ 1960 and then MCZ 5082 (Table 1). Accordingly, the holotype is currently housed in the Museum of Comparative Zoology, Harvard, as MCZ 5082. The type specimen is illustrated in Fig. 3a.There are many problems with Jackson’s (1851a, b) original description. First, many of the features included in the description are common to lower actinopterygians (such as a single triangular dorsal fin and bifurcated caudal fin) and therefore uninformative. Other details, such as the color of the scales and absence of information on the gill plates or the vertebral column, do not add relevant information to the description.Another problem deals with the holotype itself. As pointed out by Lambe (1909, 1910), MCZ 5082 is a poorly preserved specimen. There is no information about the skull. The holotype consists of a body with poorly preserved fins – pelvic fins are absent and the pectoral, dorsal, and anal fins are incomplete. Though the fulcra of the caudal fin are preserved, the caudal fin itself is highly fragmentary. Even the scales are poorly preserved – the posterior margins of the majority of the scales are broken and the ganoine ornamentation on these scales is hard to determine. The type specimen itself barely preserves any diagnostic characters (Fig. 3a).The reassignment of † Palaeoniscus [m] alberti to † Rhadinichthys alberti by Traquair (1877, 1911), Woodward (1891), Hay (1902), Eastman (1908) and Lambe (1909, 1910) was not justified or explained other than by the statement that the specimens seemed to be more closely aligned to † Rhadinichthys (Traquair, 1877). It is assumed that it is the placement of the dorsal and anal fins that justified the movement of this species to † Rhadinichthys. Lambe’s (1909, 1910) redescription does provide more diagnostic characters, but these characters are not based on what is preserved in the type specimen itself. Lambe (1909, 1910) does not identify the other specimens included in this species, nor did he detail which specimens preserve these new diagnostic characters. This reclassification also has problems because of the questions of what defines the genera † Palaeoniscum and † Rhadinichthys. In the redescription of † R. alberti, Lambe (1909, 1910) concluded that there were no differences between † R. alberti and † R. cairnsii. Jackson (1851a, b) had identified differences in the ganoine ornamentation of the scales that distinguish † R. alberti from R. cairnsii. Lambe (1909, 1910) said these differences did not exist, and so † R. cairnsii was dismantled and the specimens originally described in this species were placed into † R. alberti. Nevertheless, the type specimen of † R. cairnsii is more complete than the type specimen of † R. alberti. The type of † R. cairnsii preserves cranial information, including a tuberculated snout. Using information from the type specimen of † R. cairnsii to redescribe the taxon † R. alberti is problematic, especially when the character that is supposed to join the two taxa, ganoine ornamentation, is so unclear and poorly preserved in the type of † R. alberti.Gardiner (1966) stated that † Rhadinichthys alberti may belong to the genus † Rhadinoniscus because of features of the branchiostegal rays. This is problematic because the type specimen of † R. alberti does not preserve any clear information about the branchiostegal rays.1.4.2 † Rhadinichthys cairnsiiJackson’s (1851a, 1851b) original type for † R. cairnsii is illustrated in Fig. 3b based on MCZ 5084. The distinction between † P. cairnsii and † P. alberti was attributed to differences in the ganoine ornamentation of the flank scales; the scales of † P. cairnsii were described as having striae running parallel to the anterior and lower margins of the scales (Jackson, 1851a, b). Though the scales are not well preserved in the type of † R. alberti, Lambe determined that the same striation pattern existed in † R. alberti and † R. cairnsii, and so † R. cairnsii was not a separate species. Lambe included the former type specimen of † R. cairnsii in † R. alberti (1909, 1910). The problems with this have been discussed above.1.4.3 † Elonichthys browniiThe type specimen of † E. brownii is illustrated in Fig. 3c. Though the type specimen of † E. brownii is incomplete, the fins and scales are well preserved, (Fig. 3c). The Albert Formation specimens were most likely placed within this genus by Traquair (1877) on the basis of the large size of the fins in comparison to the other Albert Formation specimens that were placed within the genus † Rhadinichthys. As mentioned above, there is a large problem with this assignment to † Elonichthys because of our understanding of what this genus represents.The type specimen of † Palaeoniscum jacksonii (Dawson) could not be located, but based on Jackson’s (1851a, 1851b) fig. 4, plate 1, which illustrates the type of † P. jacksonii, Lambe (1909, 1910) determined it to be the same as † Elonichthys brownii.1.4.4 † Elonichthys ellsiLambe (1909, 1910) described a new species from the Albert shales based on the type and only specimen, CMN 4379. Lambe (1909, 1910) describes a unique pattern of ganoine on the anterior flank scales that defines this species. The anterior flank scales bear ridges of ganoine that “have the appearance of rows of connected tubercles” (Lambe, 1909, p. 171). Again, its placement within † Elonichthys is dubious, but the ganoine ornamentation makes it clear that this specimen is unique and different from the other previously described Albert Mine fishes. This pattern of ganoine ornamentation has not been seen in any other specimen.1.4.5 † Elonichthys († Rhadinichthys) elegantulusThe most abundant fish from the Albert shales is represented by small fusiform fishes that preserve much information regarding the scales but not much regarding the head (Lambe, 1910). These fishes were originally described by Eastman in 1908, but Lambe (1909, 1910) found this description problematic. Lambe (1910) proposed that these small and abundant specimens represent the young of one of the taxa represented by the larger specimens. Lambe (1910) concluded this on the basis of its small size and imperfect preservation, especially in regard to the head. Lambe proposed that these specimens were more similar to the body shape of † Rhadinichthys alberti than † Canobius modulus and warned that these specimens may be juvenile † R. alberti (Lambe, 1909, 1910), a statement Gardiner (1966) supported. Regardless, this species was later listed as † Rhadinichthys elegantulus by Hay (1929) and Gardiner (1966).Also problematic is the lack of type material for this species. Though there are countless small fishes with well-preserved scales, prominent lateral lines, and poorly preserved heads, we do not know which specimen Eastman used in his description. In the description of † E. elegantulus, Eastman refers to an “extensive suite of material from the Lower Carboniferous of Albert County” as well as Jackson’s original descriptions, but no specific specimens are mentioned (1908, p. 274). There are no illustrations of † E. elegantulus figured; therefore, we cannot determine which small fish specimens were studied by Eastman or which is the holotype. Gardiner (1966) mentions that the type specimen is in the Museum of Comparative Zoology, Harvard, but does not give a specimen number.1.4.6 † Canobius modulusOriginally described by Dawson (1877, 1878) as † Palaeoniscus († Rhadinichthys) modulus, this species is figured by Dawson in 1877 as fig. 1 and 1878 as fig. 18. Dawson (1877) stated that the specimen figured in Jackson’s plate II, fig. 5, “probably belongs” to this species (p. 338). Important characters noted by Dawson (1877) include 10 large oval dorsal ridge scales between the head and the dorsal fin.Woodward (1891) and Eastman (1908) reassigned † Palaeoniscum modulus to † Rhadinichthys modulus because of the reassignment of the other Albert Formation palaeoniscoids to the genus † Rhadinichthys. Eastman (1908) stated that Dawson’s original description is a composite based upon two individuals preserved on the same slab of shale. One of the specimens is incomplete and poorly preserved in comparison to the second specimen. The more complete specimen is figured by Dawson (1878), but this specimen does not preserve the dorsal ridge scales that are illustrated and described in the description. The information on the dorsal ridge scales comes from the more incomplete second specimen. Eastman (1908) provided a photograph of two specimens on a single slab of shale and described them as cotypes of † Rhadinichthys modulus. Eastman (1908) also mentioned that this specimen is housed in the Peter Redpath Museum of McGill University. Attempts to locate this specimen have so far failed.Lambe (1909, 1910) redescribed this species as † Canobius modulus. He placed the species in the genus † Canobius on the basis of the near vertical suspensorium, blunt snout, and dorsal ridge scales complete to the occiput that are seen in † Canobius but not in † Rhadinichthys. Three specimens from the Redpath Museum were examined by Lambe (1909, 1910). Moy-Thomas (1938) discussed how Westoll considered † Canobius modulus to be † R. alberti. Gardiner (1966) agreed with this and stated that † C. modulus is considered to be a “peculiarly preserved specimen of † Rhadinichthys alberti ” and then synonymized the two taxa (1966, p. 61). While Eastman (1908), Lambe (1909, 1910), and Gardiner (1966) agree that the type specimen of † C. modulus is in the Redpath Museum, McGill University, there is no record of a specimen number.1.5 Concluding remarks on redescriptions of the Albert Formation palaeoniscoidsSix species have been described from the Albert Formation, but the validity of the majority of these species has been questioned. The type specimens are either unknown, or poorly preserved. On top of this, the Albert Formation palaeoniscoids have been assigned to genera that are poorly understood, represented by poor type material, and are known to be paraphyletic. Even more problematic is how every described species has been moved from one poorly described genus to another without much justification. What we are left with is a situation where the palaeoniscoids from the Albert shale formation cannot be redescribed at this time.There are hundreds of specimens of Albert Formation palaeoniscoids in museums such as the Museum of Comparative Zoology, Harvard; the Yale Peabody Museum; the Canadian Museum of Nature; and the New Brunswick Natural History Museum. Some of these specimens are well preserved and have been previously placed within † Rhadinichthys alberti, † Elonichthys brownii, or even † Rhadinichthys cairnsii. The problem with this is that these better preserved specimens show features that are not visible in the types of the species they have been assigned to. Compounding the problem is that the features they do preserve have been used in redescriptions of the taxa. It is not possible to confidently determine if these forms belong to any species within † Rhadinichthys, † Palaeoniscum, or † Elonichthys.Problems with the paraphyly of † Rhadinichthys, † Elonichthys, and † Palaeoniscum have far-reaching effects beyond understanding the palaeoniscoids from the Albert Formation. It also impairs our understanding of the systematics of lower actinopterygians overall. Multiple species have been placed within these genera, meaning we do not understand a large portion of the lower actinopterygian diversity. Also, though many species have been described as belonging to † Rhadinichthys, † Elonichthys, and † Palaeoniscum, investigations into the relationships of lower actinopterygian fishes may include one representative species from each genus, if any. Including only one taxon from a genus known to be paraphyletic excludes a large amount of diversity and impedes recognizing problems with these genera. Future work on lower actinopterygians will necessitate redescriptions of † Rhadinichthys, † Elonichthys, and † Palaeoniscum. Until such work is done, we do not understand a large portion of the Carboniferous and Permian actinopterygian diversity.Problems with these genera have been known since the late 1800s. A concerted effort must be made to address the problems with † Rhadinichthys, † Elonichthys, and † Palaeoniscum. The condition of the type specimens may necessitate that the types are the type and only specimen of each genus. The other species placed within † Rhadinichthys, † Elonichthys, and † Palaeoniscum may need to be reevaluated and placed in new genera that can be described on the basis of informative type species. This may be the only prudent way to deal with large cosmopolitan genera described on the basis of uninformative type species. Such an undertaking is beyond the scope of this study but must be done in the near future.Rhadinichthys, Elonichthys, and Palaeoniscum were the three main Paleozoic palaeoniscoid genera in the mid-1800s. Palaeoniscum is a Permian genus and should not be considered for Early Carboniferous specimens independent of the problems of defining this genus. As for Rhadinichthys, some of the specimens from the Albert shales may belong to this genus; nevertheless, the preservation of the type specimen is so poor that assignment of this specimen to Rhadinichthys is not prudent. Future work should identify a new well-preserved specimen from museum collections and start from the beginning with the description of a new taxon.Though the fishes from the Albert Formation subscribed to the genera † Rhadinichthys, † Elonichthys, or † Palaeoniscum cannot be commented on further here, a new specimen and taxon can be described. While examining specimens of palaeoniscoids from the Albert Formation, a specimen that represents a form quite different from the type specimens of the previously described fishes was uncovered. This specimen is well preserved and can be differentiated from the previously described taxa, regardless of the condition of those type specimens. One specimen, which constitutes a new taxon from the Albert Formation, is described below.