Fossil-Lagerstätten are unusual fossil sites found across the world. They can have an abundance of fossils in one area, the fossils themselves are preserved in high quality, and many times it can be both. Normally, fossils are found mostly incomplete with just their teeth or other hard body parts preserved. However, the Earth occasionally blesses us with Lagerstätten which can amass thousands, sometimes millions of preserved fossils in stunning quality. Birds can be found with their bones perfectly intact and their feathers arranged in a beautiful display. Flowers are captured in full bloom and leaves look as if they had just fallen from its parental tree. Even amber-entombed insects have their tiny, delicate hairs untouched. Some of these fossil sites are quite well known like La Brea Tar Pits in California or Dinosaur National Monument in Utah and Colorado. Others fly under the public’s collective radar like the Grube Messel in Germany or the Naracoorte Caves in Australia. Nevertheless, these sites all contribute vast quantities of knowledge about our ancient worlds and fill in the gaps that would otherwise be empty forever.
There are two types of Fossil-Lagerstätten: Konzentrat and Konservat
- Konzentrat–Lagerstätten are sites where there is an extremely high quantity of fossils(you can remember this as konzentrat is German for concentrate). These include places like bone beds and natural animal traps. The quality of the fossils might not exceptional but the sheer number of specimens can allow us to reconstruct ecosystems and understand the life cycles of a species from infant to adult hood. La Brea Tar Pits is an example of this as millions of fossils have been discovered here.
- Konservat-Lagerstätten are fossil sites where the preservation quality of the fossil is incredibly high (again, the German word translates to the similar-sounding word “conserve”). Sometimes, the place of burial was devoid of oxygen or really salty so scavengers and decomposers couldn’t access the body. The body would thus lay untouched for millions of years. Leaves are left uncrumbled, hairs and feathers are still connected to the body, and skin deteriorates to a carbon film leaving a perfect outline of the original body. One particularly exciting example comes from Florissant Fossil Beds National Monument in Colorado. Butterflies are found with their legs and antennae; their open wings strike a beautiful pose revealing the patterns that still emboldened them. Flowers are caught in their moment of bloom and leaves retain their individual veins.
Paleontologist Dolf Seilacher coined the term in 1985. The name “Lagerstätte” is derived from a particularly rich seam of ore (a “bonanza” if you will). Combined with “fossil,” it’s defined as “rock bodies unusually rich in palaeontological information, either in a quantitative or qualitative sense.”
Sedimentological, ecological and temporal patterns of fossil Lagerstätten, Seilacher et al. 1985