Monte Leon Fm - Monte Leon (Miocene of Argentina)

Where: Argentina (50.2° S, 68.9° W: paleocoordinates 51.0° S, 62.3° W)

• coordinate based on nearby landmark

• outcrop-level geographic resolution

When: Monte Leon Formation, Early/Lower Miocene (23.0 - 16.0 Ma)

• STRATIGRAPHIC RELATIONS: From Monte Leon Fm, which is unconformably overlain by the Santa Cruz Fm (Late Miocene) and unconformably overlies the San Julian Fm (Early Oligocene). AGE: Stated in text to be Oligocene in age. Recent chronostratigraphic revision by Del Rio (2004) places the Monte Leon Fm in the Early Miocene. STRATIGRAPHIC POSITION: Upper levels of the Monte Leon Fm.

• group of beds-level stratigraphic resolution

Environment/lithology: marine; unlithified, shelly/skeletal siliciclastic sediments

• ENVIRONMENT: No environmental data reported in text, assumed to be shelfal, but not shallow water. From transgressive unit.
• SPECIFIC LITHOLOGY: Unknown lithology, assumed to be siliciclastic based on general regional geology and preservation of specimens. Highly fossiliferous. LITHIFICATION: Unlithified, assumed based on observations of figured specimens in Olivero and Camacho (1990) and Del Rio (2004).

Size class: macrofossils

Collection methods: quarrying,

• COLLECTOR: A. M. Oliveras and H. H. Camacho (1988). REPOSITORY: Catedra de Paleontologia de la Universidad de Buenos Aires (CPBA).

Primary reference: A. M. Olivera and H. H. Camacho. 1990. Revision del genero Neoimbricaria Ihering, 1907 (Gastropoda, Neogastropoda) del Oligoceno de la Argentina. Anales de la Academia Nacional de Ciencias Exactas, FĂ­sicas y Naturales, Buenos Aires 42:225-235 [A. Hendy/A. Hendy]more details

Purpose of describing collection: biostratigraphic analysis

PaleoDB collection 66154: authorized by Austin Hendy, entered by Austin Hendy on 02.10.2006, edited by Mark Uhen

Creative Commons license: CC BY (attribution)

Taxonomic list

• COVERAGE: Olivero and Camacho (1990) only list individual taxonomic group. Subsequent publications (Del Rio 2004) provide exhaustive coverage of bivalvia and gastropoda. NOMENCLATURE: Authoritative publication with modern nomenclature and species-level designations.
Gastropoda
 Neogastropoda - Mitridae
Austroimbricaria quemadensis Ihering 1897 mitre shell
Austroimbricaria gracilior Ihering 1897 mitre shell
Aves
 Cariamae - Phorusrhacidae
"Patagornis lemoinei n. sp." = Psilopterus lemoinei, "Mesembriornis studeri n. sp." = Phororhacos longissimus, "Stereornis gaudryi n. sp." = Phororhacos longissimus, "Rostrornis floweri n. gen. n. sp." = Brontornis burmeisteri
"Patagornis lemoinei n. sp." = Psilopterus lemoinei Moreno and Mercerat 1891 terror bird
"Mesembriornis studeri n. sp." = Phororhacos longissimus Ameghino 1887 terror bird
"Stereornis gaudryi n. sp." = Phororhacos longissimus Ameghino 1887 terror bird
"Rostrornis floweri n. gen. n. sp." = Brontornis burmeisteri Moreno and Mercerat 1891 terror bird