Estacao Agronomica [Estacao Limestone] (Miocene of Brazil)

Where: Para, Brazil (1.0° S, 48.0° W: paleocoordinates 1.0° S, 43.9° W)

• coordinate based on nearby landmark

• outcrop-level geographic resolution

When: Estacao Limestone Member (Pirabas Formation), Early/Lower Miocene (23.0 - 16.0 Ma)

• This collection contains all taxa not specified to either "bed 5, 6, 7, or 8" of Maury (1924). Fauna not very much like that of the Rio Pirabas outcrop, although many species are in common. Molluscan fauna indicate a Lower Miocene age. The deposit is stratigraphically near to the Pirabas Formation, but paleontological evidence is insufficient for an exact correlation. Maury (1924) suggested that it could be synchronous, slightly younger or slightly older. No specimens of Orthaulax have been ound in the fauna, suggesting a younger age, perhaps equivalent to the Gatun Fm. Simone (1994) does not illustrate any other Miocene units in the Parnaiba Basin other than the Pirabas Formation, for which I conclude the Estacao Limestone must now be considered a member of. The Pirabas Fm has a latest Late Oligocene to Middle Miocene age according text. Early Miocene in Vokes (1990), and is accordingly assigned to Early Miocene here.

• member-level stratigraphic resolution

Environment/lithology: lithified, fine-grained, shelly/skeletal, gray, calcareous limestone

• No environmental data reported.
• Fine-grained, generally grayish limestone, composed of finely ground sediments, including imperfectly preserved molluscan shells and bryozoan colonies. The limestone is highly calcareous.

Size class: macrofossils

Preservation: cast, mold/impression

Collection methods: quarrying,

• Artificial casts of the external molds were made. Collected by F. de Carvalho and Dr. Gonzaga for G. de Campos of the Brazil Geological Survey. Types are reposited at the Museum of the Brazil Geological Survey.

Primary reference: C. J. Maury. 1924. Fosseis Terciarios Do Brazil. Servico Geologico E Mineralogico Do Brazil Monographia 49 [A. Miller/A. Hendy/P. Wagner]more details

Purpose of describing collection: taxonomic analysis

PaleoDB collection 60980: authorized by Austin Hendy, entered by Austin Hendy on 28.05.2006

Creative Commons license: CC BY (attribution)

Taxonomic list

• Fairly lengthy list, but possibly not exhaustive given the quality of the fauna. The nomenclature is antiquated, though has species-resolution assignments; identifications by Maury who had extensive knowledge of circum-Caribbean faunas.
Gymnolaemata
 Cheilostomata - Lunulitidae
Bivalvia
 Nuculanida - Nuculanidae
"Leda (Adrana) agronomica n. sp." = Adrana agronomica
"Leda (Adrana) agronomica n. sp." = Adrana agronomica Maury 1924 pointed nut clam
Similar to L. (A.) aldrichiana; frail single specimen, apparently crumbled during illustration
 Arcida - Glycymerididae
Glycymeris bineminis clam
Partial internal mold and external imprint
Glycymeris cf. eumita Maury 1924 clam
 Arcida - Arcidae
Scapharca recondita n. sp. clam
Recalls: A. incile, but not Noetia; internal moold
Scapharca agraria n. sp. clam
"Scapharca ? melloi" = Scapharca (Cunearca) melloi Maury 1924 ark
Closely related member of A. transversa group
 Pectinida - Pectinoidae
Pecten cererideditus n. sp. scallop
Recalls: P. coccymelus (Mio., MD)
 Pectinida - Plicatulidae
Plicatula eroessa n. sp. scallop
 Carditida - Carditidae
 Lucinida - Lucinidae
Lucina frugalis n. sp. clam
Resembles: L. dartoni (Eoc., MD)
 Cardiida - Cardiidae
"Cardium (Trachycardium) hortensium n. sp." = Trachycardium, "Cardium (Trachycardium) viridarii n. sp." = Trachycardium, "Cardium (Fragum) estacianum n. sp." = Fragum
"Cardium (Trachycardium) hortensium n. sp." = Trachycardium cockle
"Cardium (Trachycardium) viridarii n. sp." = Trachycardium cockle
"Cardium (Fragum) estacianum n. sp." = Fragum cockle
 Cardiida - Solecurtidae
"Psammosolen cereris n. sp." = Solecurtus cereris
"Psammosolen cereris n. sp." = Solecurtus cereris Maury 1924 clam
Not unlike P. cumingianus and P. sanctidominici
 Cardiida - Veneridae
"Chione agraria" = Chione (Lirophora) agraria, Antigona proserpinae n. sp., "Pitaria vertumni n. sp." = Pitar (Lamelliconcha) vertumni
"Chione agraria" = Chione (Lirophora) agraria White 1887 venus clam
Antigona proserpinae n. sp. venus clam
Similar in sculpture to A. sanctaenoctis; several internal molds and some external imprints
"Pitaria vertumni n. sp." = Pitar (Lamelliconcha) vertumni Maury 1924 venus clam
 Cardiida - Chamidae
Echinochama pristina Maury 1924 jewel box
Several imprints and an internal mold
Chama agronomica n. sp. jewel box
 Pholadida - Corbulidae
Corbula agricolae n. sp. clam
Very rostrate
Corbula vertumni n. sp. clam
Very rostrate
Gastropoda
 Neogastropoda - Drilliidae
"Drillia consors" = Hindsiclava consors
"Drillia consors" = Hindsiclava consors Sowerby 1850 snail
Subspecies: Drillia consors pennae; external mold
 Neogastropoda - Turridae
"Pleurotoma barretti" = Polystira barretti, "Surcula (Pleurofusia) ? camposi" = Pleurofusia
"Pleurotoma barretti" = Polystira barretti Guppy 1866 turrid
molds
"Surcula (Pleurofusia) ? camposi" = Pleurofusia turrid
fragmentary external mold
 Neogastropoda - Terebridae
Terebra derbyi n. sp. auger snail
Recalls form of: T. circinata and T. serotina
Terebra estaciana n. sp. auger snail
Resembles: T. denotans
 Neogastropoda - Conidae
Conus longesperatus n. sp. cone shell
Close ally of: C. tortuosostriatus; internal mold and fragmentary imprint
 Neogastropoda - Marginellidae
Marginella estaciana n. sp. margin shell
external mold
Marginella cereris n. sp. margin shell
 Sorbeoconcha - Ficidae
"Pyrula paraensis" = Ficus paraensis
"Pyrula paraensis" = Ficus paraensis White 1887 fig shell
externa mold
 Sorbeoconcha - Cypraeidae
Cypraea pennae White 1887 cowry
fragmentary mold
 Cerithioidea - Turritellidae
Turritella agronomica n. sp. turret shell
Close to: T. meunieri
Turritella callizona n. sp. turret shell
 Trochoidea - Trochidae
Calliostoma retectum Maury 1924 top snail
very perfect external mold
Calliostoma (Eutrochus) derbyi Maury 1924 top snail
partial imprint of shell
"Solarium eudaidelum" = Trochus (Solarium) top snail
 Heterostropha - Architectonicidae
"Solarium intraornatum" = Architectonica nobilis
"Solarium intraornatum" = Architectonica nobilis Röding 1798 sundial