JUVENILE HAMITES SUBROTUNDUS

A tremendously delicate juvenile Hamites subrotundus (J. Sowerby 1814) from Upper Albian outcrops in Mallorca, the largest of the three Balearic Islands in the Mediterranean at more than 3,600 square kilometers. 

Mallorca has been home to various inhabitants for thousands of years. Sitting some 200 kilometers off Spain’s southeastern, it is a idyllic setting for exploring the rich human and geologic history of this part of the world.

The island is made up of dolomite and limestone from a huge expanse of time, the Mesozoic and Cenozoic—170 million to 10 million years ago— and bookended by two parallel mountain chains top and bottom on its southern and northern coasts. 

As you walk the mountain passes northwest to northeast, you stroll across Miocene deposits 20 million to 13 million years ago that speak of the time in our Earth's recent past when part of the African continent collided with Europe. 

It is famous for its limestone mountains and Roman and Moorish remains. As you can see here, it is also home to some rather nice fossils including this specimen of Hamites subrotundus.

While H. subrotundus is generally a Middle Albian species, this specimen was found in the lower part of Upper Albian in the Cristatum zone by José Juárez Ruiz. José had to piece this lovely together from seven fragments. His labour of love was worth the effort. The final piece is sheer perfection and a beautiful specimen approximately 2.5 cm long.

Mallorca and the other Balearic Islands are geologically an extension of the Baetic Cordillera mountain chain of western Andalusia that extends to Murcia and Valencia. 

They are made up of sediments deposited in the Tethys Sea during the Mesozoic.

Exploring the islands, you can collect from deposits from the Triassic, Cretaceous, Jurassic, and Neogene periods. 

The limestone outcrops contain lovely examples of foraminifers—mainly the species Globigerina.

We also see lovely examples of Hamites (Hamites) subrotundus in the Euhoplites loricatus zone; Euhoplites meandrinus subzone from the Middle Albian (Lower Gault) of Folkestone, Kent, UK. 

Photo, preparation and in the collection of the deeply awesome José Juárez Ruiz. Wright C. W. 1996. Treatise on Invertebrate Paleontology (Part L Mollusca 4 Revised) Volume 4: Cretaceous Ammonoidea