Alison M. Murray

The Geological, Isotopic, Botanical, Invertebrate, and Lower Vertebrate Surroundings of Ardipithecus ramidus

Sediments containing Ardipithecus ramidus were deposited 4.4 million years ago on an alluvial floodplain in Ethiopia’s western Afar rift. The Lower Aramis Member hominid-bearing unit, now exposed across a >9-kilometer structural arc, is sandwiched between two volcanic tuffs that have nearly identical 40Ar/39Ar ages. Geological data presented here, along with floral, invertebrate, and vertebrate paleontological and taphonomic evidence associated with the hominids, suggest that they occupied a wooded biotope over the western three-fourths of the paleotransect. Phytoliths and oxygen and carbon stable isotopes of pedogenic carbonates provide evidence of humid cool woodlands with a grassy substrate.

A Freshwater Ichthyofauna from the Late Eocene Birket Qarun Formation, Fayum, Egypt

ABSTRACT A collection of fossil fish teeth and other elements from Eocene deposits on the northshore of Birket Qarun, Fayum Depression, Egypt, is reported. This collection adds significantly to our knowledge, as it consists of material that was screened from the sediments, allowing collection of small teeth that represent taxa not previously reported from the Fayum. Previous collections from these sediments have concentrated on larger remains that generally represent elasmobranchs, which are marine species from deposits lower in the section. Most of this material, collected by screening at the Birket Qarun 2 (BQ-2) locality, represents fully freshwater fishes. It includes the first record of the mormyrid Gymnarchus in the Fayum Depression, which represents the oldest record for this group, known previously only from the late Miocene or younger deposits. Similarly, Mochokidae (Siluriformes) and Hydrocynus (Alestidae) remains from the site are the oldest record of these taxa. Other taxa recovered are the osteichthyans Polypterus (Polypteriformes), Protopterus (Dipnoi), and Parachanna (Channidae), and the chondrichthyans Hypolophodon cf. H. malembeensis (Dasyatoidea incert. fam.), Rhinoptera sherborni (Rhinopteridae), and Coupatezia wousteri (Dasyatoidea incert. fam.). A new ray, Coupatezia attiai, n. sp., Cook, is also described. These fishes confirm the freshwater influence at locality BQ-2 in the Birket Qarun Formation.

A new species of Sorbinichthys (Teleostei: Clupeomorpha: Ellimmichthyiformes) from the Late Cretaceous of Morocco

A new species of ellimmichthyiform fish, represented by three specimens, has been recovered from deposits of the Akrabou Formation of Morocco. The new species is described in the existing genus Sorbinichthys, family Sorbinichthyidae, as Sorbinichthys africanus, sp. nov., closely related to the type species Sorbinichthys elusivo. The Ellimmichthyiformes is an extinct order of clupeomorph fishes that includes both freshwater and marine species ranging from the Early Cretaceous through the Eocene. Sorbinichthys elusivo is known from Cenomanian deposits of the eastern Mediterranean Tethys (Lebanon), whereas the new species is possibly early Turonian but more probably late Cenomanian in age, from the western Tethys (eastern Morocco). At lower taxonomic levels, the assemblage from the Akrabou Formation has a primarily Tethyan composition, exemplified by the genus Sorbinichthys, whereas supra-generic taxa found there include groups with trans-Atlantic (e.g., Sorbinichthyidae, Macrosemiidae) or near-cosmopolitan ...

Osteoglossomorpha: phylogeny, biogeography, and fossil record and the significance of key African and Chinese fossil taxa

Abstract The Osteoglossomorpha are a clade of primitive teleostean fishes with modern representatives in five biogeogeographic regions and fossil representatives on six continents. The centre of modern diversity is in Africa but the centre of fossil diversity is in E Asia. Key fossil taxa include: †Phareodus, †Joffrichthys, and †Ostariostoma in N America; †Lycoptera, †Paralycoptera, and †Huashia among others in E Asia; †Brychaetus and possibly †Thaumaturus in Europe; †Palaeonotopterus, †Singida, and †Chauliopareion in Africa; †Tavernichthys in India; and †Musperia in SE Asia. Morphological phylogenies to date have disagreed on three main points: the relationships of †Lycoptera, of Pantodon, and of Notopterids and Mormyrids. Molecular phylogenies have similarly differed on the last two points. In this study a combined set of morphological data was generated from previous studies, including data from three recently described or redescribed taxa (the African †Singida and †Chauliopareion and the Chinese †Xixiaichthys) and maximum parsimony was used to generate a revised hypothesis of relationships. Our analysis recovered †Lycoptera, †Paralycoptera+ †Tanolepis, and †Xixiaichthys as stem-group osteoglossomorphs, †Singida as sister to Pantodon within Osteoglossidae, †Chauliopareion as a stem osteoglossid, †Ostariostoma as a stem osteoglossiform, and Notopteridae as sister to Mormyroidea and †Palaeonotopterus. These results do not lend themselves to easy explanations of osteoglossomorph biogeography involving either dispersal from a centre of origin or vicariant division of a widely distributed ancestor. Recent suggestions of an ancient (Palaeozoic) origin for osteoglossomorphs are flawed. The evidence, instead, is consistent with an origin within the Mesozoic and the biogeographic explanation involves extensive extinction of clades from continents where they occurred in the past.

A partial skeleton of the Late Cretaceous lamniform shark, Archaeolamna kopingensis, from the Pierre Shale of western Kansas, U.S.A.

ABSTRACT All previous records of the lamniform shark, Archaeolamna kopingensis, are based on isolated teeth. Here we describe a partial skeleton from the Sharon Springs Formation of the Pierre Shale Group of western Kansas, U.S.A. The specimen includes portions of the upper and lower jaws with articulated teeth. The dentition consists of two files of upper and lower anterior teeth that, together with a single file of intrabullar intermediate teeth, are housed in a dental bulla, as well as multiple files of lateral teeth, along with at least two files of lower symphysial teeth and a single file of upper symphysial teeth. The intrabullar intermediate tooth is slightly shorter than the other anterior teeth and has a median cusp with distinctive distal curvature. The dental sequence of A. kopingensis is unique among both extinct and extant lamniforms. Associated with the jaws are fragments of the neurocranium and multiple vertebral centra. A sagittal section through a centrum shows that this shark deposited 18 annual marker bands after its birth and adult size was attained by the 10th band. The robust but penetrating tooth morphology and large jaw circumference suggest that A. kopingensis likely fed upon large prey items.

A new articulated freshwater fish (Clupeomorpha, Ellimmichthyiformes) from the Horseshoe Canyon Formation, Maastrichtian, of Alberta, CanadaThis article is one of a series of papers published in this Special Issue on the theme Albertosaurus.

Horseshoeichthys armaserratus, gen. et sp. nov., (Clupeomorpha: Ellimmichthyiformes: Sorbinichthyidae) is described from the Horseshoe Canyon Formation (Maastrichtian), Albertosaurus bonebed locality, Alberta, Canada. Horseshoeichthys armaserratus is classified as an ellimmichthyiform based on the following characters: the presence of a sixth infraorbital with a sensory canal that leads to the fifth infraorbital, absence of a supraorbital bone, subrectangular predorsal scutes, parietals in contact with each other at the midline, and two supramaxillae. The specimen is classified in the Sorbinichthyidae Family as it has abdominal ribs articulating in pits on the centra, posterior spines on predorsal scutes, and absence of a median spine on predorsal scutes. A new genus and species is proposed based on the presence of (anteriorly) Y-shaped mesethmoid, supraorbital, subrectangular predorsal scutes with coarse, rounded serrae on the posterior margin and a large anterior projection, scales with serrae on the ci...

A NEW CHANNID (TELEOSTEI: CHANNIFORMES) FROM THE EOCENE AND OLIGOCENE OF EGYPT

Abstract Upper Eocene and lower Oligocene deposits of the Jebel Qatrani Formation, Fayum Depression, Egypt, have provided a number of skulls and other bones that belong to a species of snakehead (Channidae). This material is morphologically more similar to species of Parachanna, rather than species of Channa, and is here described as a new species, Parachanna fayumensis. It differs from the other species of the genus in possessing a prominent tooth patch on the posterior end of the parasphenoid. This new species of channid is the oldest member of the family known from Africa. Prior to this record, the oldest African fossil channid material was found in Mio–Pliocene deposits. This lack of information on the African fossil record leads to biogeographic reconstructions in which channids were believed to have arisen in Asia and invaded Africa through fresh waters, only after the two continents were connected in the Miocene. The Egyptian material shows that channids were in the fresh waters of Africa in the latest Eocene. Either a freshwater connection existed between Africa and Asia before or during the late Eocene, or members of the Channidae were able to migrate through marine waters to attain their current distribution.

A middle Cenomanian euselachian assemblage from the Dunvegan Formation of northwestern Alberta

A euselachian assemblage was recovered from the middle Cenomanian Dunvegan Formation situated in northwestern Alberta. This assemblage is the most northern described within the Western Interior Seaway and provides an important insight into the euselachian faunal diversity of this little-known region of the seaway. Despite its high paleolatitude, the assemblage contains a number of elasmobranch taxa, including Hybodus, Squalicorax, Archaeolamna, Cretodus, Dallasiella, and Cretoxyrhina. The Dunvegan assemblage also contains the first known reports from Canada of the odontaspid shark Johnlongia parvidens, the cretoxyrhinid shark Protolamna carteri, and the ray Pseudohypolophus mcnultyi. This assemblage extends the northern geographical range of all taxa. Preliminary comparisons with other middle Cenomanian Western Interior Seaway assemblages show that the core composition of the Dunvegan assemblage is remarkably similar to that of other time-equivalent assemblages; however, conspicuously absent are species t...

A NEW SPECIES OF LATES (TELEOSTEI: PERCIFORMES) FROM THE LOWER OLIGOCENE OF EGYPT

Abstract Early Oligocene deposits of the Jebel Qatrani Formation, Fayum Depression, Egypt, have provided three skulls that belong to a species of Lates (Perciformes, Latidae). This material differs from the other species of Lates in several features, such as the frontal bones of the fossils being broader anteriorly, the basioccipital facets having a more irregular shape, and the frontoparietal crests extending farther, and diverging, anteriorly. The Oligocene material therefore cannot be assigned to any of the described species of Lates, and is here described as a new species, L. qatraniensis. It is most similar to Lates niloticus, L. calcarifer, and L. angustifrons in the possession of an internal jugular bridge in the pterosphenoid, the parasphenoid contacting the pterosphenoid, and the anterior wall of the neurocranium (i.e., the anterior parts of the pterosphenoid, prootic, and ascending arm of the parasphenoid) extending significantly forward of the lateral commissure. Numerous cranial and postcranial elements that probably belong to the same new species are also described. This new species is the oldest Lates known from Africa.

Lower pharyngeal jaw of a cichlid fish (Actinopterygii; Labroidei) from an early Oligocene site in the Fayum, Egypt

African fossil cichlids are known from deposits ranging in age from Eocene through to Quaternary. The Eocene cichlids, five species of Mahengechromis, are from deposits in Tanzania, dated at 45 My old (Murray, 2000). Fossil cichlids probably of Oligocene age, Macfadyena dabanensis and four indeterminate forms, have come from Somalia (Van Couvering, 1982). Van Couvering (1982) also reported on isolated elements from the Early Miocene of Uganda which were identified as representing two or more species referred to Pelmatochromis, and articulated skeletons of similar age from Kenya, which she described as Palaeofulu kuluensis, Nderechromis cichloides and Kalyptochromis hamulodentis. Deposits in Kenya have also produced isolated elements of indeterminate cichlids dated as possibly Early and Late Miocene (Van Couvering, 1982). Late Miocene cichlids from Africa are Oreochromis martyni from Kenya, Palaeochromis darestei and P. rousselleti from Algeria, and unnamed remains from Kenya, Tanzania and Tunisia (Greenwood, 1973; Van Couvering, 1982; Stewart, 1997). Pliocene and Pleistocene cichlid remains include isolated bones and fragments of indeterminate species (e.g., Murray and Stewart, in press), and more complete remains referable to Recent tilapiine genera (e.g., Murray and Stewart, 1999). Lack of fossil cichlids from western Africa is probably because of a lack of deposits of an appropriate age or nature. The only fossil remains of cichlids previously reported from Egypt are isolated elements, predominantly fin spines, pterygiophores, and vertebral centra, known from Pleistocene deposits at Wadi Natrun (Greenwood, 1972). Although a number of fossil cichlids are known from Africa, additional cichlid material is necessary to better document the range of cichlids in past times. Fossil vertebrates including fishes have been reported from the Fayum Depression of Egypt, in the Western Desert about 80 km southwest of Cairo, for over 100 years. Although several teleostean fishes have been described from the Fayum, most of these are from the deposits of the Eocene Qasr el Sagha and Birket Qarun formations. These deposits are overlain by the Jebel Qatrani Formation, from which Dr. Elwyn Simons of Duke University has been actively collecting fossils for several decades. The Jebel Qatrani Formation contains deposits ranging from Late Eocene through Oligocene in age. The only fish remains that have been reported from this formation are bones of catfishes and lungfishes (Stromer, 1916; Peyer, 1928). The collections made by Dr. Simons and his team include a large amount of fish material from several localities in the Jebel Qatrani Formation. From one of these sites, Quarry E, Dr. Simons collected a lower pharyngeal jaw of a fish that is here identified as belonging to a cichlid.