Showing posts with label Tenerife. Show all posts
Showing posts with label Tenerife. Show all posts

Monday, July 27, 2020

Gibbulinella dealbata Gastropod from the Canary Islands

This last set of fossils from the Canary Islands are small and delicate. I received these as part of an exchange with a collector from Spain.  He sent me the cluster of partial shells shown below. The shells are very thin and so were packed in cotton to give them some cushioning.

Cluster 1
Cluster 2

I also received this loose shell which is in good condition.  The label that was included listed these fossils as coming from near the town of Bajamar, on the island of Tenerife.  The label had them named as "Napaeus lajaensis" but a search on Google of that species yielded examples that did not match the specimens I have in hand. N. lajaensis is a more high spired shell with the tip of the shell being pointed, not rounded to near flat like my specimens. A little bit more searching and I believe I found a more likely candidate: Gibbulinella dealbata. This page from Wikipedia shows an example that is much closer to what I have, and it lists it as being found in the Canary Islands.

So I am comfortable changing the label to Gibbulinella dealbata as that seems to be a closer match.

Right profile
Operculum
View of tip looking towards operculum
View of the bottom looking from the operculum towards the tip.

This fossil is Pleistocene in age and comes from fossilized dune deposits on the island of Tenerife in the Canary Islands, Spain.




Thursday, July 23, 2020

Thais sp.? gastropod from the Canary Islands

Below is a gastropod fossil from near the town of Taganana on the island of Tenerife, Canadry Islands, Spain.  The label that came with it identified it as "Thais speciosa". I received this fossil in an exchange with a collector in Spain so I believe it should read "Thais sp.", meaning the collector did not know what species within the genus of Thais this fossil belonged to.  I am not able to ID the shell down to the species level either, and am unsure if it even belongs in the Thais genus and the exterior shell ornamentation does not match anything I can find on Google.

The shell is longer than it is wide but does not have a high spiral. The shell is thicker than the land snail shells I received in the same trade so perhaps it is marine in origin?

I could be wrong though, any readers of this blog have an idea what this shell is?

Looking from the tip down the axis of the shell
Profile with operculum
Looking at the bottom down the axis of the shell
Profile without operculum

This fossil is Pleistocene in age and comes from soil deposits on the island of Tenerife in the Canary Islands, Spain.

Tuesday, July 21, 2020

Hemicycla collarifera gastropod from the Canary Islands

In a previous post I wrote about an insect fossil from the island of Tenerife in the Canary Islands.  In the same exchange that gave me that fossil I also received some land snail fossils from the same area.

Below is Hemicycla collarifera which is a low conispiraled gastropod similar to Hemicycla consobrina but has much more pronounced growth lines. 







This fossil is Pleistocene in age and comes from fossilized dune deposits near the town of Bajamar on the island of Tenerife in the Canary Islands, Spain.

Saturday, July 18, 2020

Hemicycla consobrina gastropod from the Canary Islands

In a previous post I wrote about an insect fossil from the island of Tenerife in the Canary Islands.  In the same exchange that gave me that fossil I also received some land snail fossils from the same area. Below is Hemicycla consobrina from Bajamar on the island of Tenerife.

Hemicycla consobrina is a low conispiraled gastropod very typical of most land snails that one finds in the woods. The shell is relatively smooth but faint ridges (growth lines) are visible.






This fossil is Pleistocene in age and comes from fossilized dune deposits on the island of Tenerife in the Canary Islands, Spain.

Wednesday, July 15, 2020

Fossil "bee cell" from Tenerife Island

Many years ago I exchanged fossils with another collector in Spain. Some of the fossils he sent were from Tenerife Island which is part of the Canary Islands. One of the more interesting fossils was one of a "fossil wasp nest".









I was dubious of the provenance of the specimen and it remained in a box until January of 2020 when I saw someone post a similar fossil on the Fossil Forum.

It was then that I did some digging and found a paper online that explains these fossils: "Fossil bee cells from the Canary Islands. Ichnotaxonomy, palaeobiology and palaeoenvironments of Palmiraichnus castellanosi", La Roche Brier, Francisco & Genise, Jorge & Castillo, Carolina & Quesada, María & García-Gotera, Cristo & Nuez, Julio. (2014).  Palaeogeography, Palaeoclimatology, Palaeoecology. 409: 249–264.  DOI: 10.1016/j.palaeo.2014.05.012

Here is a quote from the paper
6. Conclusions
1) Fossil bee cells, attributable to the ichnospecies Palmiraichnus castellanosi, are recorded from the Pleistocene and Holocene of the easternmost Canary Islands. They are single cells with ovoid to
subcylindrical shape and a discrete wall covering a chamber and an antechamber. The chamber is internally polished and is sealed by a spiral closure. The antechamber, with smooth internal walls, has a structureless active filling of the same material from the palaeosol. This record constitutes the first documented evidence for bees, and Hymenoptera, in the Quaternary of the Canaries and the first one of this ichnospecies in Africa.
 
2) Specimens of Palmiraichnus castellanosi are similar to extant cells of Andrena savignyi studied herein, regarding shape, and the presence of a discrete wall, spiral closure and antechamber. This indicates that the members of the genus Andrena (Andrenidae) were the trace makers of P. castellanosi in the Canary Islands.
 
3) The high percentage (95%) of open cells indicate a high level of breeding success, favoured by the lack of predators or parasites and optimal environmental conditions, at least in the Pleistocene.
 
4) Palaeoecological and statistical data suggest that five species may have produced Palmiraichnus castellanosi in the Canary Islands. One on Lanzarote in the Holocene, another in south Fuerteventura in the Upper Pleistocene, two on Gran Canaria during theMiddle Pleistocene (one on the north coast and the second in the east) and the last on Montaña Clara, also in the Middle Pleistocene.

5) The abundance in the Pleistocene of Palmiraichnus castellanosi in the lowlands, reflecting a large number of individuals and species of Andrena, suggests a rich flora with probably many endemic shrubby species in accordance with present and other palaeobotanical and palaeoanthropological evidences.

6) The favourable climate attested by high densities of Palmiraichnus castellanosi associated with helicids may have been similar to thatprevalent at present in the lowlands of the Canaries, but probably
with a higher MAP.

7) The land-snail assemblage associated with the low densities of Palmiraichnus castellanosi in the Holocene at mid-altitude suggests a cool moist palaeoenvironment, with lower temperatures than in
the Pleistocene lowlands,more favourable for the success of the beetle producers of Rebuffoichnus than for bees producing P. castellanosi.
Some pictures from the paper:



While I am not 100% sure the fossil I have is one of these "Bee cells" that the paper describes, it certainly looks similar.  If nothing else I at least learned a bit more about fossilization processes and paleoclimates by reading the paper.