Project Paleo: Marine Invertebrates of Southern California
Do you want to be a paleontologist? Do you want to be a curator of natural history collections? Project Paleo is your opportunity to work with fossils and contribute to the curation of Natural History Museum of Los Angeles County collections.
Stay tuned for news on how can you be involved!
The fossil media in your kit is a mixture of marine fossils and waste material. Your task is to find and separate the complete fossils and return them for curation at the Natural History Museum of Los Angeles County.
The fossil record tells about environments and events long ago and helps us make decisions about the future. We want to share the discovery of fossils with you!
The fossils in this sorting kit were collected near San Pedro, not far from downtown Los Angeles. Through much of the last million years coastal Los Angeles has been underwater. Scientists believe these fossils were living around 300,000 years ago. Can you help us figure out what the environmental was like at this time by sorting and identifying these fossils?
When this kit is returned to the Natural History Museum of Los Angeles County these fossils will be added into our collection, and you will be acknowledged as their collector. Good luck junior paleontologists!
The Project Paleo kit contains: 1 sorting tray, magnifying lens, paint brushes, large and small zip-lock bags, identification labels, laminated instructions and identification guides, and a bag of unsorted fossil media. If you run out of bags, please feel free to add your own zip-locks to the kit (snack or sandwich size work well).
How to sort fossils:
The Natural History Museum of Los Angeles County will generally only curate specimens from the Project Paleo kits that can be easily identified. For bivalves, specimens should include part or all of the hinge (beak and teeth) of the shell. For gastropods, specimens should include part or all of the aperture (opening) of the shell. All other fragments may be placed back in the original bag of matrix.
When identifying, pay close attention to the large differences in the size, shape, color patterns, and sculpture of specimens.
Size: All organisms grow up from small individuals and so it is possible to observe juvenile individuals of larger specimens. However, specimens that appear considerably larger than those figured in identification resources (printed to full size) might indicate a misidentification.
Shape: Shape is generally consistent among all individuals of a species, although pay close attention to the left and right valves of a bivalve, which are typically a mirror image of each other. An exception are specimens of Ostrea conchaphila (southern Olympic oyster) and Anomia peruviana (Peruvian jingle shell), which have an irregular and highly variable shape.
Color patterns: Color is generally not preserved in fossils, although those of Pleistocene age (last 2 million years) are more likely to retain such patterns. In particular, look for nacre (shiny lustre) that might help differentiate Anomia from Ostrea. Other taxa that exhibit nacre include Nucula and Pandora.
Sculpture: Sculpture is perhaps the easiest feature to observe after shell shape. Bivalves may have:
- no sculpture or a smooth exterior surface (e.g., Caryocorbula, Cryptomya, Donax, Macoma, Nutrricola, Tagelus)
- concentric sculpture, which is parallel to the shell margin (e.g., Amiantis, Crassinella)
- radial sculpture, which radiates out from the beak or hinge of the shell (e.g., Argopecten, Leptopecten, Mexicardia)
- cancellate sculpture, where both concentric and radial ribs form a lattice or net-like pattern (e.g., Chione, Lucinisca, Nucula)
- irregular ridges, bumps, or divots (e.g., Ostrea, Anomia)
Gastropods may have:
- no sculpture or a smooth surface (e.g., Alia, Californiconus, Callianax, Crepidula, Glossaulax, Littorina)
- spiral sculpture, where ribs, ridges or channels are parallel to the whorls (e.g., Eulithidium, Turritella)
- axial sculpture, where ribs or ridges are parallel to the axis of growth of the shell (e.g., Cerithideopsis, Hima, Phrontis)
- cancellate sculpture, where both spiral and axial ribs form a lattice or net-like pattern (e.g., Caesia)
- irregular ridges, bumps, or divots (e.g., Crucibulum).
The scaphopod (tusk shell) Dentalium is characterized by 4-6 ridges running down the length of the shell. You may also find other species of tusk shells, which may be smooth and/or smaller than Dentalium neohexagonum. Depending on the species or body part, barnacles may be smooth or have radial ribs, are often red, brown, or pink, and have a honeycomb internal structure.