3.4 Paleontology
Donovan et al. (2005) indicated that the knowledge of echinoid fossils from Belize
is poorly documented. In their paper they reported the presence of two echinoids:
Echinolampas sp. cf. aldrichi from the Mid Miocene to Quaternary, and
Echinocorys sp. cf. scutata from the Mid Eocene. Gischler (2010) analyzed five
Holocene sediment cores from Glovers and Lighthouse reefs, and Turneffe islands,
Belize. He picked out echinoid spines, plates, and teeth. These were identified to
genus based on comparison with these pieces of echinoids collected live and
treated with dilute sodium hypochlorite and dried. A few fragments of the massive
spines of E. tribuloides and the burrowing echinoid Clypeaster were found in cores
from Turneffe. Diadema and Echinometra pieces were the most commonly
encountered. Gischler (2010) reported that three significant echinoid mass mortality events occurred during 6.3–6.1 kyr BP (Glovers reef) as well as 4 and 1.3 kyr
BP (Turneffe Islands). The first mass mortality event apparently only affected
Diadema. The second and third events affected both Diadema and Echinometra.
Alvarado et al. (2006) reviewed echinoderm paleontological research that
occurred from 1880 until 2001 in Costa Rica, and listed 46 species. The fauna is
composed of Crinoidea with one genus and Echinoidea with seven orders, 18
families, 28 genera and 45 species. Of the echinoids, the order Spatangoida was
the most diverse, with seven families, 15 genera and 26 species. Within this order,
the most diverse family was Brissidae, with eight genera. The genus Schizaster had
seven species. They indicated that the majority of species are Cretaceous and
Miocene, from 11 geological formations. The fossil echinoderm fauna of Costa
Rica is similar to other areas of CA and México, with a good record from the
Miocene and a notable decline to the Pliocene (Buitrón 1978). Alvarado et al.
(2006) pointed out that a greater effort is needed in the investigation of fossil
echinoderms to improve its understanding, and to have a real appreciation of its
composition. Specimen identification, due to lack of specialists and literature, is
one of the greatest problems. There is also a need to explore more areas in CA.
3.5 Threats to Echinoderms
Echinoderms are vulnerable to a number of threats from natural and anthropogenic
origin. The threats can also be classified as directly or indirectly related to echinoderms. Any deterioration of the environment where the echinoderms live can be
classified as an indirect threat. Because the majority of echinoderms in CA live in
shallow coastal waters, the most important habitats are coral reefs, rocky reefs and
seagrass meadows. All threated due to human activity.
Cortés (2007) indicated the main natural disturbances to coral reefs in CA are
the following: (1) extensive mortality of corals due to bleaching associated with
extremes in water temperature or salinity, sediment or bacterial infection;
3 Central America Echinoderms: Diversity, Ecology and Future Perspectives
95
Donovan et al. (2005) indicated that the knowledge of echinoid fossils from Belize
is poorly documented. In their paper they reported the presence of two echinoids:
Echinolampas sp. cf. aldrichi from the Mid Miocene to Quaternary, and
Echinocorys sp. cf. scutata from the Mid Eocene. Gischler (2010) analyzed five
Holocene sediment cores from Glovers and Lighthouse reefs, and Turneffe islands,
Belize. He picked out echinoid spines, plates, and teeth. These were identified to
genus based on comparison with these pieces of echinoids collected live and
treated with dilute sodium hypochlorite and dried. A few fragments of the massive
spines of E. tribuloides and the burrowing echinoid Clypeaster were found in cores
from Turneffe. Diadema and Echinometra pieces were the most commonly
encountered. Gischler (2010) reported that three significant echinoid mass mortality events occurred during 6.3–6.1 kyr BP (Glovers reef) as well as 4 and 1.3 kyr
BP (Turneffe Islands). The first mass mortality event apparently only affected
Diadema. The second and third events affected both Diadema and Echinometra.
Alvarado et al. (2006) reviewed echinoderm paleontological research that
occurred from 1880 until 2001 in Costa Rica, and listed 46 species. The fauna is
composed of Crinoidea with one genus and Echinoidea with seven orders, 18
families, 28 genera and 45 species. Of the echinoids, the order Spatangoida was
the most diverse, with seven families, 15 genera and 26 species. Within this order,
the most diverse family was Brissidae, with eight genera. The genus Schizaster had
seven species. They indicated that the majority of species are Cretaceous and
Miocene, from 11 geological formations. The fossil echinoderm fauna of Costa
Rica is similar to other areas of CA and México, with a good record from the
Miocene and a notable decline to the Pliocene (Buitrón 1978). Alvarado et al.
(2006) pointed out that a greater effort is needed in the investigation of fossil
echinoderms to improve its understanding, and to have a real appreciation of its
composition. Specimen identification, due to lack of specialists and literature, is
one of the greatest problems. There is also a need to explore more areas in CA.
3.5 Threats to Echinoderms
Echinoderms are vulnerable to a number of threats from natural and anthropogenic
origin. The threats can also be classified as directly or indirectly related to echinoderms. Any deterioration of the environment where the echinoderms live can be
classified as an indirect threat. Because the majority of echinoderms in CA live in
shallow coastal waters, the most important habitats are coral reefs, rocky reefs and
seagrass meadows. All threated due to human activity.
Cortés (2007) indicated the main natural disturbances to coral reefs in CA are
the following: (1) extensive mortality of corals due to bleaching associated with
extremes in water temperature or salinity, sediment or bacterial infection;
3 Central America Echinoderms: Diversity, Ecology and Future Perspectives
95