Editing Monte Bolca

{{short description|Frazione of Italy}}{{Coord|45|35|43|N|11|12|36|E|type:mountain_region:IT|display=title}}

{{Infobox rockunit
|name=Monte Bolca
|period=Ypresian
|age=Late [[Ypresian]], {{fossil range|50|49}}
|subunits=Pesciacara, Monte Postale, Purga di Bolca, Vegroni
|country={{Flag|Italy}}
|namedfor=[[Bolca]], Italy
|type=[[Lagerstätte]]
|prilithology=[[Limestone]], [[marl]], [[lignite]]
|otherlithology=[[Volcaniclastic]]
|region=[[Veneto]]|namedby=[[Giovanni Serafino Volta]]|year_ts=1789|paleocoordinates={{coord|37.3|N|10.3|E|display=inline}}|coordinates={{coord|45.6|N|11.2|E|display=inline}}|image=Photo Massimiliano Cerato during fossil extraction operations at the Cave della Pesciara on Monte Purga near Bolca 1964 - Touring Club Italiano 07 0547.jpg|caption=Fossils being excavated from the ''Pesciara'' site, ca. 1964|map={{Location map+ | Italy
| relief = 1
| width   = 250
| float   = center
| places  =
  {{Location map~ | Italy
  | lat_deg = 45.6
  | lon_deg = 11.2
  | mark = Lightgreen pog.svg
  | marksize = 10
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}}}}
'''Monte Bolca''' is an [[Ypresian|Early Eocene]]-aged geologic site located near [[Verona, Italy|Verona]], [[Italy]]. A ''[[Konservat-Lagerstätte]]'', it contains an extremely well-preserved and diverse marine biota, including the most diverse fish fauna of any Cenozoic fossil site, as well as many of the earliest fossil occurrences of modern marine fish groups. It was one of the first fossil sites with high quality preservation known to Europeans, with studies of its biota dating back to the 18th century and earlier, and is still an important source of fossils.<ref name=":0">{{Cite journal |last=Friedman |first=Matt |last2=Carnevale |first2=Giorgio |date=2018 |title=The Bolca Lagerstätten: shallow marine life in the Eocene |url=https://www.lyellcollection.org/doi/10.1144/jgs2017-164 |journal=Journal of the Geological Society |language=en |volume=175 |issue=4 |pages=569–579 |doi=10.1144/jgs2017-164 |issn=0016-7649|url-access=subscription }}</ref>

==History==
Strictly speaking, the Monte Bolca site is one specific spot near the village of Bolca in Italy, known as the ''Pesciara'' ("The Fishbowl") due to its many extraordinarily well preserved [[Eocene]] [[fish fossil]]s.<ref>{{cite book |editor1-first=D.J. |editor1-last=Bottjer |editor2-first=W. |editor2-last=Etter |editor3-first=J.W. |editor3-last=Hagadorn |editor4-first=C.M. |editor4-last=Tang |title=Exceptional Fossil Preservation |publisher=[[Columbia University Press]] |year=2001}}</ref> However, there are several other related outcroppings in the general vicinity that also carry similar fossils, such as Monte Postale and Monte Vegroni.<ref>Williams, Matt, [http://palaeo.gly.bris.ac.uk/palaeofiles/lagerstatten/monte_bolca/location.html Location of Monte Bolca], University of Bristol</ref> The term Monte Bolca is used interchangeably to refer to the one, original site, or to all the sites collectively.

The fossils at Monte Bolca have been known since at least the 16th century,<ref name="Miller">{{cite book |author=William Miller, III |url=https://books.google.com/books?id=FLDKUSoFmHMC&pg=PA224 |title=Trace Fossils: Concepts, Problems, Prospects: Chapter 13 "''Zoophycos'' and the Role of Type Specimens in Ichnotaxonomy by Davide Olivero |date=13 October 2011 |publisher=Elsevier |isbn=978-0-08-047535-6 |pages=224–226 |accessdate=1 April 2013}}</ref> though the first extensive research was conducted on them by [[Giovanni Serafino Volta]] in the late 18th century.<ref name=":0" /> They were studied intensively in the 19th century once it was definitively proven that fossils were the remnants of dead animals.

Fossils from Monte Bolca are commonly available for sale by commercial fossil dealers, and due to their popularity and preservation regularly sell for several hundred dollars.

==Geology==
All sites referred to as being a part of Monte Bolca are located in the eastern part of Monti Lessini near Verona, northern Italy.<ref>{{Cite journal |last=Marramà |first=Giuseppe |last2=Carnevale |first2=Giorgio |last3=Kriwet |first3=Jürgen |date=December 2021 |title=Diversity, palaeoecology and palaeoenvironmental significance of the Eocene chondrichthyan assemblages of the Bolca Lagerstätte, Italy |url=https://doi.org/10.1111/let.12436 |journal=Lethaia |volume=54 |issue=5 |pages=736–751 |doi=10.1111/let.12436 |issn=0024-1164|hdl=2318/1795500 |hdl-access=free }}</ref> This area represents a continuation of the [[Southern Alps]]. Though all of these sites have been put under a single name, there is not a place called "Monte Bolca". Due to the differences in the environment and stratigraphy, more recent authors have also called these sites the Bolca Lagerstätten.<ref name=":1" />

Due to volcanic events that had taken place in the area, a number of tectonic disturbances are present which were a result of the uplift of the ‘‘Trento Plateau’’. The nonuniform uplift of this plateau also caused the creation of the Lessini Shelf which was the northernmost margin of the [[Adriatic plate|Adriatic Plate]]. Multiple authors have mentioned a sub-vertical fault that runs north northwest-south southeast just west of Bolca.<ref>{{Cite journal |last=Trevisani |first=Enrico |date=2015-04-14 |title=Upper Cretaceous-Lower Eocene succession of the Monte Postale and its relationship with the “Pesciara di Bolca” (Lessini Mountains, northern Italy): deposition of a fossil-fish lagerstätte |url=https://doi.org/10.1007/s10347-015-0431-y |journal=Facies |volume=61 |issue=3 |doi=10.1007/s10347-015-0431-y |issn=0172-9179|url-access=subscription }}</ref> However, more recent work done at Monte Postale has not seen the presence of this supposed fault and has since been discarded.<ref name=":1">{{Cite journal |last=Friedman |first=Matt |last2=Carnevale |first2=Giorgio |date=2018-05-08 |title=The Bolca Lagerstätten: shallow marine life in the Eocene |url=https://doi.org/10.1144/jgs2017-164 |journal=Journal of the Geological Society |volume=175 |issue=4 |pages=569–579 |doi=10.1144/jgs2017-164 |issn=0016-7649|url-access=subscription }}</ref><ref>{{Cite journal |last=Papazzoni |first=Cesare Andrea |last2=Fornaciara |first2=Eliana |last3=Giusberti |first3=Luca |last4=Vescongni |first4=Alessandro |last5=Fornaciari |first5=Beatrice |date=January 2017 |title=Integrating Shallow Benthic and Calcareous Nannofossil Zones: The Lower Eocene of the Montef Postale Section (Northern Italy) |url=https://doi.org/10.2110/palo.2016.014 |journal=PALAIOS |volume=32 |issue=1 |pages=6–17 |doi=10.2110/palo.2016.014 |issn=0883-1351|hdl=11577/3224576 |hdl-access=free }}</ref>

=== Spilecco ===
Spilecco, also known as Spilecco Hill, is largely made up of poorly-exposed reddish marly and grey-green [[Limestone|limestones]]. While the fossil content of the grey-green limestones is made up of various microfossils, macrofossils are found in the reddish marly limestones. The strata within Spilecco date from the Thanetian to lower Ypresian which make them the oldest shallow water deposits in the Lessini Shelf and would have been deposited after the first period of volcanic activity.<ref name=":2">{{Cite journal |last=Seghetti |first=Simone Matteo |last2=Georgalis |first2=Georgios L. |last3=Tschopp |first3=Emanuel |last4=Delfino |first4=Massimo |date=2022 |title=A historical overview of the reptile fauna from the Eocene Bolca Fossil-Lagerstätte (Italy) |journal=Bollettino della Società Paleontologica Italiana |volume=61 |issue=2}}</ref><ref name=":3">The  Bolca  Fossil-Lagerstätten: A  window  into  the  Eocene  World</ref>

=== Pesciara ===
The Pesciara site of Monte Bolca is made up of a sheet-like limestone in the form of an olistolith which has an area of a few hundred square meters and is under 20 m thick. <ref>{{Cite journal |last=Trevisani |first=Enrico |last2=Papazzoni |first2=Cesare Andrea |last3=Ragazzi |first3=Eugenio |last4=Roghi |first4=Guido |date=August 2005 |title=Early Eocene amber from the “Pesciara di Bolca” (Lessini Mountains, Northern Italy) |url=https://doi.org/10.1016/j.palaeo.2005.04.008 |journal=Palaeogeography, Palaeoclimatology, Palaeoecology |volume=223 |issue=3-4 |pages=260–274 |doi=10.1016/j.palaeo.2005.04.008 |issn=0031-0182|url-access=subscription }}</ref> Throughout this bed, there are both reef and alveoline limestones which are medium-fine grained. The different limestone beds alternate between the fossiliferous laminites and more course-grained biocalcarenites and biocalcirudites. These more course layers are a lot less fossiliferous though still contain fossils such as foraminifera and mollusks. Most fossils within the Persciara site have been found within five of the levels with the 1st, 2nd, and 5th levels being the most productive. However, due to being completely excavated over the last four centuries, the 5th level is no longer accessible. <ref name=":02">{{Cite journal |last=Pasini |first=Giovanni |last2=Garassino |first2=Alessandro |last3=De Angeli |first3=Antonio |last4=Hyžný |first4=Matúš |last5=Giusberti |first5=Luca |last6=Zorzin |first6=Roberto |date=2019-09-25 |title=Eocene decapod faunas from the Konservat-Lagerstätten laminites of “Pesciara” (Bolca, Verona) and Monte Postale (Altissimo, Vicenza) in northeast Italy: a review and update |url=https://doi.org/10.1127/njgpa/2019/0840 |journal=Neues Jahrbuch für Geologie und Paläontologie - Abhandlungen |volume=293 |issue=3 |pages=233–270 |doi=10.1127/njgpa/2019/0840 |issn=0077-7749}}</ref> Towards the south-east of the deposit, the limestone layers dip at a 24° angle which suggests that the beds slid towards the north-west when they were more plastic. Volcanoclastic rock surrounds the limestone beds and due to this isolation, there has been trouble in understanding the relationship between the Pesciara and Monte Postale sites.<ref>{{Cite journal |last=Dal Degan |first=Davide |last2=Barbieri |first2=Simone |date=2005 |title=Rilievo geologico dell'area di Bolca (Monti Lessini orientali) Geological survey of the Bolca area (Eastern Lessini Mountains) |journal=Bollettino del Museo civico di Storia Naturale di Verona |volume=27}}</ref><ref name=":3" /> Due to the foraminifera and other fossils found at the site, Pesciara has been assigned to the late Ypresian.<ref name=":02" />

=== Monte Postale ===
The Monte Postale site of Monte Bolca is located north of Pesciara and represents a succession with a thickness of over 130 m. Throughout this complex succession, there are transitions from fine-grained limestones to massive coralgal limestones.<ref name=":02" /> These coralgal limestones are highly abundant in coral colonies and range from weakly to massive stratification. The thicker logs of the coralgal limestones are about 13.7 m in thickness each with the finer-grained logs being thinner. Within all of these logs, there is ''Alveolina'' present however it is much more common in the coarser-grained sediments. <ref name=":4">{{Cite journal |last=Vescogni |first=Alessandro |last2=Bosellini |first2=Francesca R. |last3=Papazzoni |first3=Cesare Andrea |last4=Giusberti |first4=Luca |last5=Roghi |first5=Guido |last6=Fornaciari |first6=Eliana |last7=Dominici |first7=Stefano |last8=Zorzin |first8=Roberto |date=2016-06-02 |title=Coralgal buildups associated with the Bolca Fossil-Lagerstätten: new evidence from the Ypresian of Monte Postale (NE Italy) |url=https://doi.org/10.1007/s10347-016-0472-x |journal=Facies |volume=62 |issue=3 |doi=10.1007/s10347-016-0472-x |issn=0172-9179|url-access=subscription }}</ref> Though the site is largely known for the fish and plants found, Monte Postale is also well known for the molluscan fauna located at the uppermost section of the site. Just like Pesciara, the stata of Monte Postale have been dated to the late Ypresian with the upper-most portion of the beds being potentially correlated to the limestones seen at Pesciara.<ref name=":02" />

=== Purga di Bolca and Vegroni ===
Unlike Pesciara and Monte Postale, Purga di Bolca and Vegroni are representative of freshwater to brackish environments. Both localities are within a volcanic cone whose base has been dated to the Ypresian, similar to the other sites of Monte Bolca. Purga di Bolca is made up of silts, clays, and lignites with contain the vertebrates and mollusks of these localities. This locality is preserved as a conical hill and ranges between 10-20 m in thickness. Under these strata there are tuffaceous layers containing palms. The succession between the two is interrupted by layers of basalt. Though the base of the cone date to a similar age to the other sites, this more terrestrial environment is younger than the above mentioned marine strata. The palm beds found in the Vegroni locality have been dated to the early Oligocene while the basaltic layer have been dated to the Bartonian.<ref name=":2" /> The correlation between these more terrestrial and marine faunas have long been problematic.<ref name=":1" />

==Species in the formation==
{{Main|Paleobiota of Monte Bolca}}

=== Animal fossils ===
[[File:Ceratoichthys pinnatiformis 4554.jpg|thumb|The bizarre [[Carangidae|jackfish]] ''[[Ceratoichthys]]'']]
[[File:FOS658A.jpg|thumb|The small [[herring]] relative ''[[Bolcaichthys]]'' is the most common fish of the formation]]
[[Image:Naturkundemuseum Berlin - Archaeophis proavus Massalongo - Monte Bolca.jpg|thumb|right|The marine snake ''[[Archaeophis|Archaeophis proavus]]'' Massalongo, Museum für Naturkunde (Berlin).|234x234px]]Monte Bolca is rich in fish: 250 species (140 genera, 90 families and 19 orders).<ref name="Fauna">Williams, Matt, [http://palaeo.gly.bris.ac.uk/palaeofiles/lagerstatten/monte_bolca/faunaandflora.html Fauna and Flora of Monte Bolca] {{Webarchive|url=https://web.archive.org/web/20160327110602/http://palaeo.gly.bris.ac.uk/Palaeofiles/Lagerstatten/monte_bolca/faunaandflora.html |date=2016-03-27 }}, University of Bristol</ref>    Additionally a cephalopod, crustaceans, jellyfish and polychaete worms have been found whole, but foraminifera, molluscs, and corals are found in fragments and may have been transported.<ref name="Fauna" />  Bird feathers and tortoise shell plates have been found, as well as many insects, freshwater and land plants.<ref name="Fauna" />

Notable fossil species include: 
{{Div col|colwidth=22em}}
*'''[[Fish]]''' 
** ''[[Angiolinia|Angiolinia mirabilis]]'', an [[Zanclidae|zanclid]] [[fish]]
** ''[[Bolcaperca|Bolcaperca craccorum]]'', an [[Percoidei|perch]]
** ''[[Blochius]] longirostris'', an [[swordfish|ancestral swordfish]]
** ''[[Ceratoichthys]]'', an unusual [[Carangidae|jack fish]]
** ''[[Bolcaichthys]]'', a [[herring]] relative and the most abundant fish of the formation
** ''[[Cyclopoma]] gigas'', a large [[percomorph]]
** ''[[Eastmanalepes|Eastmanalepes primaevus]]'', a jack fish
** ''[[Eolactoria|Eolactoria sorbinii]]'', a [[Ostraciidae|boxfish]]
** ''[[Eoplatax]] papilio'', a [[Platax|batfish]] 
** ''[[Exellia velifer]]'', a [[Ephippidae|spadefish]] 
** ''[[Godsilia lanceolata]]'', a primitive [[tuna]]
** ''[[Eolates]]'', a [[Lates|relative]] of the [[Nile perch]]
** ''[[Caruso brachysomus]]'', a primitive [[anglerfish]]
** ''[[Mene rhombea]]'' and ''[[Mene oblonga]]'', early [[Mene|moonfish]]
** ''[[Paranguilla|Paranguilla tigrina]]'', an [[eel]] with preserved coloration
** ''[[Pasaichthys|Pasaichthys pleuronectiformis]]'', a [[Monodactylidae|mooneyfish]]
** ''[[Platax]] altissimus'' and ''Platax macropterygius'', [[spadefish]]
** ''[[Platinx]]'', one of the last [[crossognathiform]] fish
** ''[[Proaracana|Proaracana dubia]]'', an [[Aracanidae|aracanid boxfish]]
** ''[[Protobalistum|Protobalistum imperial]]'', a relative of boxfish and triggerfish
** ''[[Psettopsis|Psettopsis subarcuatus]]'', a mooneyfish
** ''[[Pycnodus]] platessus'', one of the last [[pycnodont]] fish
** ''[[Pygaeus]] nobilis'', a bony-fish
** ''[[Serranus]] occipitalis'', a [[Serranidae|sea bass]]
** ''[[Sharfia mirabilis]]'', an anglerfish
** ''[[Sphyraena bolcensis]]'', one of the earliest [[Barracuda|barracudas]]
** ''[[Spinacanthus|Spinacanthus cuneiformis]]'', a [[Tetraodontiformes|relative]] of boxfish and [[triggerfish]]
** ''[[Zorzinichthys]]'', a zorzinichthyid percomorph
*'''[[Shark|Sharks]]'''
** ''[[Galeorhinus cuvieri]]'', a relative of the modern [[school shark]]
** ''[[Eogaleus]]'', an early [[requiem shark]]
** ''[[Brachycarcharias]]'', a [[sand shark]]
*'''[[Ray (fish)|Rays]]'''
** ''[[Arechia|Arechia crassicaudata]]'', an [[Urolophidae|stingaree]]
** ''[[Dasyomyliobatis]]'', a [[stingray]] intermediate between [[whiptail stingray|whiptail stingrays]] and [[eagle rays]]
** ''[[Lessiniabatis]]'', a bizarre stingray with a highly reduced tail
*'''[[Lobster]]'''
**''[[Justitia (crustacean)|Justitia]] desmaresti''
*'''[[Crocodile]]'''
**''[[Crocodylus|Crocodilus]] vicetinus''
*'''[[Snake|Snakes]]'''
** ''[[Archaeophis]] bolcaensis''
** ''Archaeophis proavus'' 
*'''[[Cephalopoda|Cephalopods]]'''
** ''[[Bolcaoctopus|Bolcaoctopus pesciaraensis]]'', an [[octopus]]
{{div col end}}

===Plant fossils===
[[File:Photo Natural History Museum of Verona. Fossil of an undetermined terrestrial plant branch found in the deposits of the Cave della Pesciara on Monte Purga near Bolca. 1964 - Touring Club Italiano 07 0527.jpg|thumb|267x267px|A well-preserved tree branch recovered from Bolca]]
One of the more interesting puzzles in ichnotaxonomy, pertains to fossils from Monte Bolca, originally named ''[[Zoophycos]] caput-medusae'', previously thought to be [[trace fossil]]s, were found to be plants instead and given the name [[Algae|Algarum]] by French zoologist [[Henri Milne-Edwards]] in 1866.<ref name="Miller" />  The type specimen collected by Italian [[Paleobotany|paleobotanist]]  [[Abramo Bartolommeo Massalongo]] before 1855 is at the Natural History Museum of [[Verona]] and was preserved in a [[lithographic limestone]] upper and lower slab.<ref name="Miller" />

When Italian [[Botany|botanist]] Achille Forti (28 November 1878 Verona -11 February 1937  Verona) worked on the specimens in 1926, they were reinterpreted as close relatives of the sea palm, now known to be a [[brown algae]], which had lived in the [[Neritic zone|coastal waters]] of the Eocene sea.<ref name="Miller" />  He renamed the species ''Postelsia caput-medusae'' which makes it related to the genus ''[[Postelsia]]'', now with only one living species, which was described by its discoverer [[Franz Josef Ruprecht]] in 1852 as ''Postelsia palmaeformis''.<ref name="Miller" />   His type-specimen is from [[Bodega Bay, California]],<ref name="Miller" />  but the species is found along the Pacific coast.  The appearance of the plant is a holdfast on the bottom, with a stem-like stipe between there and the fronds which are about {{convert|5|cm|in}} to {{convert|10|cm|in}}.<ref name="Miller" />   In life, the fronds hang vertically when the tide is in but flop over the stipe when exposed by low tide.<ref name="Miller" />

Curiously, other specimens from this deposit collected and described by Massalongo in 1855 were actually trace fossils, only this one was a plant.<ref name="Miller" />

==See also==
* [[List of fossil sites]] ''(with link directory)''

==References==
{{Reflist}}
{{commons category|Monte Bolca}}

==External links==
* [https://web.archive.org/web/20100526075559/http://www.fossilis.fr/ PDF Les fossiles de Bolca] - Fossils of Bolca - I fossili di Bolca
* [https://web.archive.org/web/20061202132421/http://www.mnhn.fr/museum/front/medias/publication/8116_g06n2a5.pdf PDF Fishes from the Eocene of Bolca],  Bannikov, Alexandre, Geodiversitas 28 (2): 249-275

[[Category:Paleontological sites of Europe]]
[[Category:Eocene Europe]]
[[Category:Lagerstätten]]
[[Category:Paleogene Italy]]
[[Category:Paleontology in Italy]]
[[Category:Archaeological sites in Veneto]]
[[Category:Geography of Veneto]]
[[Category:History of Veneto]]
[[Category:Ypresian Stage]]
[[Category:Shallow marine deposits]]