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Geoconservation Research
2021, Volume 4 / Issue 1 / pages(56-60)
European UNESCO Geoparks: Short Communication
1 Department of Earth Sciences, University of Huelva, Av. Fuerzas Armadas, s/n, 21071 Huelva, Spain
2 CCTH - Science and Technology Research Centre, University of Huelva, Avda. Fuerzas Armadas, s/n, E-21071 Huelva, Spain
3 Department of Earth Sciences -IUCA. University of Zaragoza, 50009 Zaragoza, Spain
4 Department of Botany and Geology, University of València, E-46100 Burjassot, Spain
5 Department of Geosciences, Faculty of Sciences & Information Technology, Universiti Teknologi Petronas (UTP), 32610 Bandar Seri Iskandar (Perak), Malaysia
6 Department of Specific Didactics-IUCA, University of Zaragoza, E-50009 Zaragoza, Spain
7 Centro de Geociências, Universidade de Coimbra, Rua Sílvio Lima, 3030-790 Coimbra, Portugal
8 Parque Natural Sierra Norte de Sevilla – Geoparque Mundial de la UNESCO, E-41071 Spain
Abstract
Some exceptional paleontological trilobite sites located in the Sierra Norte de Se- villa UNESCO Global Geopark are presented herein, together with an analysis of their geotourism / geotrail potential and a proposal for geoconservation. The sites are of Marianian age, a regional stage and age of the Cambrian Mediterranean Subprovince which was defined within the territory of the Geopark. This area con- stitutes the type area of six trilobite genera and twelve trilobite species and other associated faunas (hyolith, serpulid and echinoderm species).
Keywords: Fossils, Trilobita, Paleontological heritage, Seville, Spain.
Article information | |
Received: 2020-10-14 Accepted: 2021-04-04 DOI: 10.30486/GCR.2021.1912240.1044 How to cite: Mayoral E, Liñán E, Gozalo R, Gámez Vintaned JA, Dies Álvarez6, Luis Collantes ME, Santos A & Gil-To- ja A (2021). Early Cambrian (Marianian) trilobites and associated faunas from the Sierra Norte de Sevilla Geopark: A scientific and heritage approach. Geoconservation Research: 4(1):56-60. doi: 10.30486/gcr.2021.1912240.1044 Geoconservation Research e-ISSN: 2588-7343 p-ISSN: 2645-4661 © Author(s) 2020, this article is published with open access at http://gcr.khuisf.ac.ir |
The Sierra Norte de Sevilla Geopark was first nom- inated as a Spanish Natural Park in 1989. In 2011, it was declared a European Geopark and later recog- nized as a UNESCO World Geopark in 2015.
The unique paleontological features and the inter- national recognition of the Early Cambrian trilo- bite sites within the geopark are briefly presented in this work. Following the discovery of the first trilobite site in 1938, about 20 Early Cambrian tri- lobite sites have been reported since then. They occur in the Benalija Unit near the municipalities of Cazalla de la Sierra, Guadalcanal, San Nicolás del Puerto and Constantina. These discoveries
resulted in several studies published by some of the most renowned Cambrian specialists from the 20th century, namely Richter and Richter (1940), Hupé (1953), Hennigsmoen (1958) and Sdzuy
(1961, 1962). See Mayoral et al. (2008) and May- oral et al. (2020) for more recent studies.
The trilobite sites occur in the Ossa-Morena Zone (Iberian Massif; Fig. 1A), in Cambrian outcrops of the northern limb of the Olivenza-Monesterio Antiform (Fig. 1B). More specifically, they are within the Benalija Unit (Fig. 1C). The sites are scattered throughout the stratigraphic succession of the Lower Cambrian Alanís Beds (Fig. 2).
Figure 1. Location of the studied area. A. Ossa-Morena Zone (framed area). B. Cambrian outcrops and location of the Sierra Norte de Sevilla Geopark. C. Main sites with fauna of the Early Cambrian (Benalija Unit) in the Sierra Norte de Sevilla Geopark. Geological map modified from TRAGSATEC (2011).
Figure 2. Synthetic Lower Cambrian stratigraphy of the area.
A total of 16 genera and 18 species of trilobites have been recognized in the Sierra Norte de Sevil- la Geopark, one of the highest trilobite diversities worldwide for this geological time interval. The geopark also includes the original locations – type area, or locus typicus – where several trilobite genera were defined, namely Alanisia, Saukian- da, Perrector, Eops, Strenuaeva and Andalusiana (Fig. 3), as well as those of other species including twelve trilobites, one hyolith, one serpulid and one echinoderm.
In addition, the Sierra Norte de Sevilla Geopark is the type area where the Marianian Stage (from the Latin Mons Mariani = Sierra Morena) was defined. The Marianian is a formal geological unit of ref- erence for the Cambrian Mediterranean Subprov- ince. The presence of Early Cambrian soft-bodied fossils was evidence to include this Geopark in the list of exceptional Lagerstätten sites, highlighting the scientific value of the sites in terms of natural heritage and the need for their conservation.
From a strictly scientific perspective, one of the most outstanding characteristics of the Geopark is that it allows the possibility of analyzing, both temporally and spatially, the variation in trilobite faunal assemblages and, therefore, to interpret the
changes in the communities of successive ecosys- tems. Furthermore, the Geopark offers the possi- bility of recognizing different paleoenvironments which range from coastal (Cerro del Hierro event) to marine platforms, with benthic and pelagic fos- sil fauna present, such as some tiny, pelagic eodis- cid trilobites which are characteristic of the Lower Cambrian of both North America and Europe.
The trilobite sites of the Sierra Norte de Sevilla Geopark have reached peak popularity since their first discovery in Alanís almost 100 years ago. Sci- entific expeditions by universities from Germany, France, Sweden, Belgium and Spain, as well as from international museums, have improved the geological and paleontological knowledge of the sites, and also their national and international im- pact (Liñán 2004).
The geoturism and geotrail potential is consid- erable. So far, a geological guide for the Sierra Norte Natural Park, now Sierra Norte de Sevilla Geopark (Moreno et al. 2008), as well as a pale- ontological route established within the Cerro del Hierro site (Mayoral et al. 2008), have been pub- lished. The Sierra Norte de Sevilla Geopark fea- tures well-developed touristic facilities, including several free public access routes, together with some other restricted trails used by authorized
Figure 3. Most representative trilobites of the Sierra Norte de Sevilla Geopark and some associated fauna. A) Andalusiana cornuta Sdzuy. B-C) Alanisia guillermoi Richter & Richter. C) Cranidium. D) Eops sp. E. Exuviae of gigantopygid trilobite. F) Saukianda andalusiae Richter & Richter. G) Strenuaeva sampelayoi Richter & Richter.
H) Acrothele sp., an inarticulate brachiopod. All scale bars = 1 mm, except for A = 5 mm.
touristic-educational companies, one Information Point and some other facilities which adequately complete the services offered to visitors.
The Sierra Norte de Sevilla Geopark finds its
background in the declaration of the area as a Nat-
ural Park by the Law 2/1989, of 18 July, which ap- proved the Inventory of Protected Natural Spaces in Andalusia. Furthermore, although the protection status of these paleontological sites is high, there are still potentially serious threats of uncontrolled exploitation of some trilobite sites highly desired by collectors. The future inclusion of the trilobite sites in the Andalusian Inventory of Georesources and the Geosites Inventory of the Sierra Norte de Sevilla Geopark will undoubtedly increase their conservation enforcement.
The Cambrian paleontological sites with trilobites and associated faunas in the Sierra Norte de Sevil- la Geopark have a significant richness and a high heritage and historical value. Furthermore, the privileged geological environment where they are located makes them ideal for future exhibitions and the creation of new paleontological itinerar- ies and georoutes, thus increasing the international projection of this Geopark.
We acknowledge support from the Research Group RNM276 of the Junta de Andalucía (Spain), and from the Science and Technology Research Cen- tre, University of Huelva.
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