Laganum depressum agassiz (Echinodea, Laganidae) : a new record from the Maltese tertiary

Abstract

The genus Laganum is recorded for the first time from the Maltese tertiary and from the whole Mediterranean region, on the basis of a single speciment of Laganum depressum Agassiz reputedly collected from the reef-bearing Upper Coralline Limestron (Upper Miocene, Tortonian) at Il-Karraba, N.W. Malta. It is now limited to Indo-Pacifics waters and its record from the Maltese Tertiary not only confirms the presence of a former communication existing between European Tethys and the Indo-Pacific during Miocene times, but also increases still further the Indo-Pacific affinity of Maltese Tertiary faunas. The Maltese Laganum depressum Agassiz is described and compared with similar Laganum material originating from distant geographical areas and now in the British Museum (Nat. Hist.) Collections. As the characteristic internal structure of laganum is revealed by industrial radiography, the use of the genus is in doubt, particularly when it has to be differentiated from the apparantly similar Clypeaster.