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Silveirinha Formation

{{Short description|Geologic formation in Portugal}}

{{Infobox rockunit

| name = Silveirinha Formation

| period = Ypresian

| age = Ypresian
(MP7 or Neustrian)
~{{fossil range|55.8|48.6}}

| image =

| imagesize =

| caption =

| type = Geological formation

| prilithology = Sandstone, siltstone

| otherlithology = Conglomerate

| unitof =

| subunits = Rio Mondego Member

| underlies = Bom Sucesso Formation

| overlies = Taveiro Formation

| thickness =

| location =

| coordinates = {{coord|40.0|N|8.8|W|display=inline,title}}

| paleocoordinates = {{coord|35.6|N|10.0|W|display=inline}}

| region = Região Centro

| country = Portugal

| extent = Mondego Basin

| namedfor = Silveirinha clay pit

| namedby = Autunes et al.

| year_ts = 1981

| location_ts = Silveirinha clay pit

| coordinates_ts = {{coord|40|00|29.0|N|8|49|16.7|W|display=inline}}

| paleocoordinates_ts =

| region_ts = Coimbra District

| country_ts =

| thickness_ts =

| area =

| map = {{Location map+ | Portugal

| relief = 1

| width = 250

| float = center

| places =

{{Location map~ | Portugal

| lat_deg = 40.0

| lon_deg = -8.8

| mark = Orange pog.svg

| marksize = 12

}}

}}

| map_caption =

}}

The Silveirinha Formation is an Early Eocene (Ypresian, or MP7 or Neustrian in the ELMA classification) geologic formation of the Mondego Basin in the Região Centro of central-western Portugal. The sandstones, siltstones and conglomerates were deposited in an alluvial environment.[https://paleobiodb.org/classic/displayCollResults?collection_no=79200 Silveirinha Formation] at Fossilworks.org

The formation has provided fossils of many mammals, birds, amphibians and reptiles, as well as mollusks and ostracods, and is considered one of the richest Early Eocene faunal assemblages of Europe. The taeniodont, typically known as a North American order; Eurodon silveirinhensis and the ostracod Cypris silveirinhaensis have been named after the formation.

Description

The Silveirinha Formation, named after the Silveirinha clay pit, crops out in the western part of the Mondego Basin in the Região Centro of central-western Portugal.De la Peña, 1995, p.30 The formation comprises fossiliferous lenticular calcitic conglomerates as well as laminated and cross bedded sands and brownish-red silts.

The conglomerates are interpreted as crevasse-splay deposit in a alluvial plain environment, which eventually flooded and where bogs and possibly oxbows developed, crossed by channels depending on a river system that drained higher areas more north or eastwards.Antunes, 2003, p.20

= Climate =

{{see also|Paleocene-Eocene Thermal Maximum}}

The climate in the Early Eocene was substantially warmer than today.

Paleontological significance

The Silveirinha clay pit after which the formation is named was first discovered in 1977 by Rui Pena dos Reis of Coimbra University. The unit is one of few earliest Eocene fossiliferous formations that provided a rich amphibian and reptile fauna.Rage & Augé, 2003, p.103 Most fossils were deposited in the channels after short transportation. Vegetation should have been rich in nearby areas, supporting a rich fauna. Ostracods,

gastropods, amphibians and pelomedusid chelonians indicate fresh waters, although rare bivalves show that salt or at least brackish waters were not very far away.

It is hypothesized that the species D. antunesi in the genus Diacodexis was more primitive than the earliest Wasatchian D. ilicis of North America, strongly supporting a Europe to America dispersal of this genus.Godinot & De Lapparent, 2003, p.262

= Fossil content =

The formation has provided the following fossils:

== Mammals ==

;Primates

;Acreodi

;Artiodactyls

;Carnivora

;Cimolesta

;"Condylartha"

;Ferae

;Glires

;Hyaenodonta

;Insectivora

;Perissodactyls

{{div col|colwidth=29em}}

{{div col end}}

;Taeniodonta

;Theriiformes

{{div col|colwidth=29em}}

{{div col end}}

== Birds ==

== Reptiles ==

;Crocodiles

;Lizards

{{div col|colwidth=29em}}

{{div col end}}

;Snakes

;Turtles

== Amphibians ==

== Invertebrates ==

;Mollusks

{{div col|colwidth=29em}}

{{div col end}}

;Ostracods

See also

{{div col|colwidth=35em}}

{{div col end}}

References

{{reflist}}

= Bibliography =

  • {{citation |last1=Tabuce |first1=Rodolphe |first2=Julien |last2=Clavel |first3=Miguel Telles |last3=Antunes |year=2011 |title=A structural intermediate between triisodontids and mesonychians (Mammalia, Acreodi) from the earliest Eocene of Portugal |url=https://www.researchgate.net/publication/49705008 |journal=The Science of Nature |volume=98 |issue=2 |pages=145–155 |doi=10.1007/s00114-010-0747-y |pmid=21181109 |bibcode=2011NW.....98..145T |access-date=2020-09-06}}
  • {{citation |last1=Tabuce |first1=R. |first2=M. T. |last2=Antunes |first3=B. |last3=Sige |year=2009 |title=A new primitive bat from the earliest Eocene of Europe |journal=Journal of Vertebrate Paleontology |volume=29 |issue=2 |pages=627–630|doi=10.1671/039.029.0204 |bibcode=2009JVPal..29..627T }}
  • {{citation |last1=Tabuce |first1=Rodolphe |first2=Miguel Telles |last2=Antunes |first3=Richard |last3=Smith |first4=Thierry |last4=Smith |year=2006 |title=Dental and tarsal morphology of the European Paleocene/Eocene 'condylarth' mammal Microhyus |url=https://www.app.pan.pl/article/item/app51-037.html |journal=Acta Palaeontologica Polonica |volume=51 |pages=37–52 |access-date=2020-09-06}}
  • {{citation |last=Antunes |first=M. T |year=2003 |title=Lower Paleogene crocodilians from Silveirinha, Portugal |journal=Palaeovertebrata |volume=32 |pages=1–26 |s2cid=132993434 }}
  • {{citation |last=Callapez |first=Pedro |year=2003 |title=Upper Paleocene-Early Eocene mollusks of Silveirinha (Figueira da Foz, West Central Portugal) |journal=Ciências da Terra |volume=15 |pages=83–90}}
  • {{citation |last1=Colin |first1=Jean-Paul |first2=Miguel Telles |last2=Autunes |year=2003 |title=Limnic ostracoda from Silveirinha, Portugal (? Late Paleocene - Lowermost Eocene) |journal=Ciências da Terra |volume=15 |pages=91–100}}
  • {{citation |last1=Rage |first1=J. C. |first2=M. |last2=Augé |year=2003 |title=Amphibians and squamate reptiles from the lower Eocene of Silveirinha (Portugal) |url=https://www.researchgate.net/publication/279767266 |journal=Ciências da Terra |volume=15 |pages=103–116 |access-date=2020-09-06}}
  • {{citation |last=de Lapparent de Broin |first=F |year=2003 |title=Neochelys sp. (Chelonii, Erymnochelyinae), from Silveirinha, early Eocene, Portugal |url=https://www.researchgate.net/publication/256843854 |journal=Ciências da Terra |volume=15 |pages=117–132 |access-date=2020-09-06}}
  • {{citation |last1=Godinot |first1=Marc |first2=France |last2=de Lapparent de Broin |year=2003 |title=Arguments for a mammalian and reptilian dispersal from Asia to Europe during the Paleocene-Eocene boundary interval |url=https://www.researchgate.net/publication/256843857 |journal=Deinsea |volume=10 |pages=255–275 |access-date=2020-09-06 |issn=0923-9308}}
  • {{citation |last=Estravís |first=C |year=2000 |title=Nuevos mamíferos del Eoceno Inferior de Silveirinha (Baixo Mondego, Portugal) |journal=Coloquios de Paleontología |volume=51 |pages=281–311 |s2cid=161766178 }}
  • {{citation |last=Escarguel |first=Gilles |year=1999 |title=Les rongeurs de l'Eocène inférieur et moyen d'Europe occidentale - Systématique, phylogénie, bio-chronologie et paléobiogéographie des niveaux-repères MP7 a MP14 |url=https://www.researchgate.net/publication/232613068 |journal=Palaeovertebrata |volume=28 |pages=89–351 |access-date=2020-09-06}}
  • {{citation |last=Estravís |first=C |year=1996 |title=Leptacodon nascimentoi n. sp., un nouveau Nyctitheriidae (Mammalia, Lipotyphla) de l'Eocène inférieur de Silveirinha (Baixo Mondego, Portugal) |journal=Palaeovertebrata |volume=25 |pages=279–286}}
  • {{citation |last=De la Peña Zarzuelo |first=Antonio |year=1995 |title=Los Peces terciarios de las cuencas continentales ibéricas: Marco histórico y registro fosil conocido - Tertiary fishes from the Iberia continental basins: History and fossil record |url=https://dialnet.unirioja.es/servlet/articulo?codigo=169680 |journal=Coloquios de Paleontología |volume=47 |pages=25–46 |access-date=2020-09-06 |issn=1132-1660}}
  • {{citation |last=Estravís |first=C |year=1994 |title=Microparamys paisi, un nouvel Ischyromyidae (Rodentia) de l'Éocène inférieur de Silveirinha (Baixo Mondego, Portugal) |journal=Comptes Rendus de l'Académie des Sciences de Paris |volume=318 |pages=417–420}}
  • {{citation |last1=Estravís |first1=Carmen |first2=Donald E. |last2=Russell |year=1992a |title=The presence of Taeniodonta (Mammalia) in the Early Eocene of Europe |journal=Ciências da Terra |volume=11 |pages=191–201 |s2cid=59471522 }}
  • {{citation |last1=Estravís |first1=Carmen |first2=Donald E. |last2=Russell |year=1992b |title=Paschatherium marianae, un nouveau Condylarthra de Silveirinha, Éocène inferérieur du Portugal |journal=Bulletin du Muséum National d'Histoire Naturelle, Section C |volume=14 |pages=185–203}}
  • {{citation |last=Estravís |first=C |year=1990 |title=Russellmys denisae, un nouvel Apatémyidé (Mammalia) de Silveirinha, eocène inférieur du Portugal |journal=Geobios |volume=23 |issue=6 |pages=761–765|doi=10.1016/S0016-6995(06)80342-6 |bibcode=1990Geobi..23..761E }}
  • {{citation |last1=Estravís |first1=C. |first2=D. E. |last2=Russell |year=1989 |title=Decouverte d'un nouveau Diacodexis (Artiocactyla, Mammalia) dans l'Eocène inférieur de Silveirinha, Portugal |journal=Palaeovertebrata |volume=19 |pages=29–44}}
  • {{citation |last1=Antunes |first1=M.T. |last2=Estravís |first2=C. |last3=Russell |first3=D.E. |year=1987 |title=A new condylarth (Mammalia) from the Early Eocene of Silveirinha, Portugal |journal=Münchner Geowissenschaftliche Abhandlungen A |volume=10 |pages=219–224}}
  • {{citation |last=Harrison |first=C. J. O |year=1983 |title=A new wader, Recurvirostridae (Charadriiformes), from the Early Eocene of Portugal |journal=Ciencias da Terra |volume=7 |pages=9–16}}

Category:Geologic formations of Portugal

Category:Eocene Series of Europe

Category:Paleogene Portugal

Category:Ypresian Stage

Category:Conglomerate formations

Category:Sandstone formations

Category:Siltstone formations

Category:Alluvial deposits

Category:Fossiliferous stratigraphic units of Europe

Category:Paleontology in Portugal

Formations

Formations