San Gerardo de Limoncito (Neogene of Costa Rica)

Where: Puntarenas, Costa Rica (8.9° N, 83.1° W: paleocoordinates 8.9° N, 83.1° W)

• coordinate stated in text

• small collection-level geographic resolution

When: Curré Formation, Hemphillian (10.3 - 4.9 Ma)

• Age: Late Hemphillian (Hh3) (Late Miocene), Curré Formation, San Gerardo de Limoncito, Costa Rica. 87Sr/86Sr 5.80 Ma +/- 0.60/-0.80

•The rock unit that contains the fossiliferous remains corresponds to the Curré Formation. Henningsen (1965) defines this formation as a series of tuffaceous sandstones with intercalations of conglomerates, siltstones and occasionally shales, dark green and brownish green when altered. Mora (1979), describes two subunits according to their sedimentological characteris- tics: The subunit of volcaniclastic conglomerates of gray-green color, overlain by shales that settled in a transitional environ- ment between delta and beach. The subunit of black shales, interspersed with strata of sandstones and fine conglomerates, was deposited in a paralic environment of estuary or swamp type. They are very chloritized and basically consist of subvolcanic products.

•The paleontological material recovered is housed at the Geology Section of the Natural History Department at The National Museum of Costa Rica, and comes from a level of fine conglomerate that is located towards the roof of a sequence of blue clays, which in turn is overlain by a sequence of medium to fine sandstones, which confirms its association with the superior subunit or subunit of shales (sensu Mora, 1979). Granados and Aguilar (1983), based on the presence of molluscs, obtained a Middle-Late Miocene age for the Curré Formation.

• group of beds-level stratigraphic resolution

Environment/lithology: deltaic; conglomerate

• Subaquatic fan delta: The lithofacies of conglomerates is what characterizes this depositional environment and is composed of blue clay intraclasts, coming from the lower level which it overlies at an erosional discordance. The clasts have diameters that vary between 5 and 13 cm; they are well rounded, little or not spherical; some have point contact, but 90% of them float in a matrix of glauconitic clay. The clasts are arranged with their long axis parallel to the layer of stratification, and it is possible to observe some degree of imbrication. In this sequence are frequent bone and dental remains of various vertebrates, both terrestrial and marine. The Trypanites ichnofacies, in this case, is inferred indirectly from the blue clay intraclasts that are usually perforated by bivalves of the family Pholadidae, from which it is still possible to find remains of the valves within the fossil traces of Gastrochaenolites sp.

Size class: macrofossils

Primary reference: C. A. Laurito and A. L. Valerio. 2008. The first record of Gavialosuchus americanus Sellards (1915)† (Eusuchia: Crocodylidae, Tomistominae) for the Late Tertiary of Costa Rica and Central America. Revista Geológica de América Central 39:107-115 [P. Mannion/P. Mannion]more details

Purpose of describing collection: taxonomic analysis

PaleoDB collection 144596: authorized by Philip Mannion, entered by Philip Mannion on 13.05.2013, edited by Evangelos Vlachos, Juan Carrillo, Miranta Kouvari and Grace Varnham

Creative Commons license: CC BY (attribution)

Taxonomic list

Chondrichthyes
 Myliobatiformes - Myliobatidae
Myliobatis sp.2 Cuvier 1816 eagle ray
Rhinoptera sp.2 Cuvier 1829 cownose ray
 Myliobatiformes - Aetobatidae
Aetobatus arcuatus2 Agassiz 1843 stingray
 Myliobatiformes - Dasyatidae
Dasyatis cavernosa2 Probst 1877 whiptail stingray
 Carcharhiniformes - Carcharhinidae
Isogomphodon acuarius2 daggernose shark
Isogomphodon caunellensis2 daggernose shark
Carcharhinus longimanus2 requiem shark
Carcharhinus priscus2 Agassiz 1843 requiem shark
 Carcharhiniformes - Hemigaleidae
Hemipristis serra2 Agassiz 1835 ground shark
 Carcharhiniformes - Sphyrnidae
Sphyrna arambourgi2 hammerhead shark
 Lamniformes - Lamnidae
"Isurus desorii" = Isurus oxyrinchus2
"Isurus desorii" = Isurus oxyrinchus2 Rafinesque 1810 mackerel shark
Mammalia
 Perissodactyla - Equidae
Dinohippus mexicanus1, "Calippus (Grammohippus) hondurensis" = Calippus hondurensis1, Protohippus gidleyi1
Dinohippus mexicanus1 Lance 1950 horse
"Calippus (Grammohippus) hondurensis" = Calippus hondurensis1 Olson and McGrew 1941 horse
Protohippus gidleyi1 Hulbert 1988 horse
 Artiodactyla - Tayassuidae
Tayassuidae indet.2 Palmer 1897 peccary
Protherohyus brachydontus9 Dalquest and Mooser 1980 peccary
CFM-2195
Prosthennops serus9 Cope 1877 peccary
CFM-2915, CFM-1861, CFM-1862, CFM-1499, CFM-1652,CFM-1651,
 Artiodactyla - Camelidae
"Hemiauchenia vera" = Pleiolama vera5
"Hemiauchenia vera" = Pleiolama vera5 Matthew 1909 camel
 Cingulata - Pampatheriidae
Scirrotherium antelucanus n. sp.4 Laurito and Valerio 2013 edentate
Holotype CFM 2867
 Megatherioidea - Megalonychidae
Pliometanastes cf. protistus3 Hirschfeld and Webb 1968 edentate
CFM-2017, and 2645
Zacatzontli cotobrusensis n. sp.10 Valerio et al. 2022 edentate
Holotype: CFM-2916; CFM-2917, first upper molariform; CFM-1000, molarifiorm. CFM-1000 and CFM-2917 were previously referred to as Pliometanastes cf. protistus
 Megatherioidea - Megatheriidae
Sibotherium ka n. gen. n. sp.7
Sibotherium ka n. gen. n. sp.7 Rincón et al. 2020 edentate
  - Mylodontidae
Mylodontidae indet.2 Ameghino 1889 edentate
 Proboscidea - Gomphotheriidae
Rhynchotherium blicki8 Frick 1933 gomphothere
CFM-2837, 3224, 3361, 3364 and 3365
Reptilia
 Testudines - Emydidae
Emydinae indet.2 Rafinesque 1815 turtle
 Testudines - Trionychidae
Apalone sp.6 Rafinesque 1832 softshell turtle
CFM-1163-1166 and 1193, Five shell specimens
 Crocodylia -
"Gavialosuchus americana" = Thecachampsa sericodon
"Gavialosuchus americana" = Thecachampsa sericodon Cope 1867 crocodilian
CFM-1793 (jaw fragments), CFM-1792 (jaw fragment) and CFM-960, 972, 1774, 1912, 1913, 1916 & 1923 (osteoderms)
Actinopteri
 Perciformes - Sparidae
Sparus sp.2 Linnaeus 1758 perch-like fish
 Siluriformes - Ariidae
Arius sp.2 Cuvier and Valenciennes 1840 Ariid catfish