Francisco J. De Figueiredo

A new clupeiform fish from the Lower Cretaceous (Barremian) of Sergipe-Alagoas Basin, northeastern Brazil

ABSTRACT Fossil remains of clupeomorph fishes are commonly found in Cretaceous and Tertiary deposits from the northeastern Brazil. The taxonomic diversity is relatively high and include †ellimmichthyiforms, early clupeiforms, and advanced clupeoids. However, well-preserved specimens are very scarce so that very little is known about affinities of most taxa. Recently, new localities containing clupeomorphs have been discovered and prospected in Alagoas State, in Northeastern Brazil. From them, Atol Quarry, in which Barremian shales from the Coqueiro Seco Formation crop out, has demonstrated to be meaningful by having a diverse fish assemblage. It contains holosteans, coelacanths, gonorynchiforms, and enchodontids besides clupeomorphs. Most of fishes correspond to new taxa. In this paper, an early clupeiform fish, †Pseudoellimma gallae gen. et sp. nov., is described from those shales. The fish shows many informative characters and revealed to be advanced in comparison with other early and relatively well-known clupeomorphs such as †Spratticeps and †Santanaclupea. Although lacking pleurostyle, it shares with clupeoids derived features such as accessory anterior foramen of temporal canal, hidden post-orbital branch of supraorbital canal on frontal, longitudinal and parallel ridges sculpturing the skull roof, and reduced first ural centrum. If so, many derived features found in advanced extant clupeoids appeared early in the history of clupeiform fishes. Furthermore the present study indicates divergence between Clupeoidei and Denticipitoidei lineages older than Barremian age.ABSTRACT Fossil remains of clupeomorph fishes are commonly found in Cretaceous and Tertiary deposits from the northeastern Brazil. The taxonomic diversity is relatively high and include tellimmichthyiforms, early clupeiforms, and advanced clupeoids. However, well-preserved specimens are very scarce so that very little is known about affinities of most taxa. Recently, new localities containing clupeomorphs have been discovered and prospected in Alagoas State, in Northeastern Brazil. From them, Atol Quarry, in which Barremian shales from the Coqueiro Seco Formation crop out, has demonstrated to be meaningful by having a diverse fish assemblage. It contains holosteans, coelacanths, gonorynchiforms, and enchodontids besides clupeomorphs. Most of fishes correspond to new taxa. In this paper, an early clupeiform fish, †Pseudoellimma gallae gen. et sp. nov., is described from those shales. The fish shows many informative characters and revealed to be advanced in comparison with other early and relatively well-known clupeomorphs such as † Spratticeps and † Santanaclupea. Although lacking pleurostyle, it shares with clupeoids derived features such as accessory anterior foramen of temporal canal, hidden post-orbital branch of supraorbital canal on frontal, longitudinal and parallel ridges sculpturing the skull roof, and reduced first ural centrum. If so, many derived features found in advanced extant clupeoids appeared early in the history of clupeiform fishes. Furthermore the present study indicates divergence between Clupeoidei and Denticipitoidei lineages older than Barremian age.

Pelotius hesselae, gen. et sp. nov. (Teleostei: Holocentridae) from the Cretaceous (Turonian) of Pelotas Basin, Brazil

ABSTRACT The first holocentroid fish from South America, Pelotius hesselae gen. et sp. nov., is described from the Turonian of the Atlântida Formation, Pelotas Basin, southern Brazil. It is a small fish preserved in a dark gray neritic shale from a drill-core sample collected at a depth of around 4,000 m. The inclusion of P. hesselae in the Holocentroidei is supported by the presence of four spines in the anal fin, the penultimate one being the longer, and an expanded neural spine of the fourth preural centrum. Although preservation is insufficient to permit detailed morphological description of the skull and caudal skeleton, the high number of dorsal spines (10), the median suture in the posterior portion of the pelvic bone, and the presence of seven rays in the pelvic fin exclude Pelotius from the Trachichthyoidei, Stichocentridae and Pycnosteroididae and suggest its inclusion in the Holocentridae. On the other hand, it shares with the clade Erygocentrus + Tenuicentrinae + Myripristinae + Holocentrinae ...

Relationships of †Codoichthys carnavalii Santos, 1994 (Teleostei, Clupeomorpha, †Ellimmichthyiformes) from the Late Aptian of São Luís-Grajaú Basin, NE Brazil

†Codoichthys carnavalii is a clupeomorph fish only found in calcareous concretions of Codó Formation, State of Maranhão. It is known based on three specimens housed in the paleontological collection of the Museu de Ciências da Terra of Departamento Nacional da Produção Mineral, Rio de Janeiro. It was omitted in most of recent cladistic analyses about clupeomorphs. We revisited its anatomy furnishing new data and additional restorations. Furthermore we explored the relationships of †Codoichthys with the computer program TNT based on a matrix with 30 taxa and 60 unordered and unweight characters. Elops was used to root the tree. The strict consensus was obtained from three shortest trees (L=181; CI=0.387; RI=0.632). The monophyly of †Ellimmichthyiformes is supported by a sigmoid cleithrum and an uniquely derived predorsal scute series. Most of subgroups showed low support indices. †Sorbinichthyidae and †Horseshoeichthys appear in the most basal position, and not closely related to †Armigatus or †Diplomystus. A †Diplomystus clade is more advanced than †Armigatus and sister-group of remaining †ellimmichthyiforms. Within †Paraclupeidae, †Codoichthys is sister-group of remaining †paraclupeids (including †thorectichthyines and †paraclupeines). Within †Paraclupeinae, †Triplomystini includes a †Triplomystus clade, a sister group of †Rhombichthys plus †Tycheroichthys, and †Paraclupeini with †S. itapagipensis and all other †ellimmichthyiform taxa.

Distributional patterns of Aptian-Albian paleoichthyofauna of Brazil and Africa based on Track Analysis

The Aptian-Albian paleoichthyofauna in Brazil and Africa is quite diverse, yet their geographic patterns still require accounts. This work consists of a panbiogeographical analysis of paleoichthyofauna from Aptian-Albian through track analysis. Geographic coordinates were obtained and converted into paleocoordinates. Individual Tracks (ITs) and Generalized Tracks (GTs) were built with the aid of ArcView GIS v3.2 program using Trazos2004 extension. As a result, four GTs and tree Biogeographic Nodes (A, B and C) had been identified. GTs 1 and 2 shows two different faunas. GT3 indicates similarity between Brazil and Africa paleoichthyofauna suggesting the break-up of Gondwana as the event that separated it. GT4 represents a probable local seaway produced by transgressions. In the Node A a unique fauna was found indicating the presence of a third biota with its own characteristics. Node B is associated with the break-up of the supercontinent Gondwana. Node C was related to fauna exchange promoted by marine ingression and epicontinental seas that occurred during Aptian-Albian. We concluded that there is a relationship between the distributional patterns of biota and events such as the break-up of Gondwana, the formation of Atlantic Ocean and eustatic movements that affected South America and Africa.