In the year 1995 an old lady donated a 120 million year old fish to the Geosciences Collection. She has lived in South America for many years and was cherishing the fossil as a souvenir from Brazil. This fossil fish was housed for many years in a drawer of the collection before it was realised as a rare garfish. Preparing a special exhibition in 2001 the head of the collection recognised the actual identity.
Fossils of fossil fishes from Brazil are housed in geological collections all over the world, consequently most species have been recorded since the last or even last but one century. Fossil garfishes, however, are unknown before 1992. They are very rare and in high demand from scientists. Each fossils provides important hints about the evolution of these fishes that are “living fossils” and have been unmodified until recent times. This is the reason why the news about this new valuable fossil found its way very quickly to the United States. A specialist in fossil fishes in Chicago borrowed it from the collection to investigate it properly.
“Living fossils” and the fossils of the Santana Formation
The fossil fish can be assigned to Obaichthys decoratus, a species first descriobed by Wenz & Brito (1992). The fossil comes from the world-famous Santana Formation in Brazil and is consequently early Cretaceous in age (Martill 1993, 2001). Dr. Lance Grande, palaeontologist and specialist for fossil fishes at the Field Museum in Chicago, borrowed the fossil and made a scientific description. The Geosciences Collection houses fossils from the Santana Formation of Brazil that have been purchased between 1895 and the turn of the century by the former museum for natural history, ethnology and trading of the city of Bremen. A label showing the words “From the lower stream of the Amazons (further information not yet available)” shows that there was little knowledge about these Brazilian fossils even 80 years after discovering these fossil sites. Actually, the locality in Brazil is located about 1000 km southeast of the lower part of the “stream of Amazons”, the river Amazon. This makes the specimen valuable for the history of palaeontology.
Garfishes are ethnic bony fishes that still exist in the rivers of North and Middle America as well as Cuba. They are known as “living fossils” since they have not changed significantly from the Cretaceous period until recent days. Their usually thick scales are built up of enamel making them “ethnic”, not known in modern bony fishes. The vertebral column is, however, solid bone in contrast, for example, to the sharks and rays that show a comparatively simple skeleton of cartilage.
The German term for garfish means bony pike. However, garfishes are distinguished from the more progressive “actual” pikes by their thick scales built up of enamel that is as hard as bone (that is where the term is derived from) as well as a differently shaped and snout-like prolonged jaw. Like pikes, garfishes are predators in rivers and lakes.
References:
- Martill, D. M. (1993): Fossils of the Santana and Crato Formations, Brazil. – Field Guide to Fossils 5, The Palaeontological Association, London, 159.
- Martill, D. M. (2001): The Santana Formation. – In: Briggs, D. E. G. & Crowther, P. R. (Hrsg.): Palaeobiology II, Oxford, Blackwell, 351-356.
- Wenz, S. & Brito, P. M. (1992): Première découverte de Lepisosteidae (Pisces, Actinopterygii) dans le Crétacé Inférieur de la Chapada do Araripe (N-E du Brésil): consequences sur la phylogenie des Gynglymodi. – Comptes Rendus de l’Academie des Sciences 314: 1519-1525.