As we recently reported, scientists were astonished to stumble across the bones of ancient mammoths and bison aged between 50,000 and 200,000 years old from the last Ice Age while workers were building a new housing development in California. But it’s not even close to the weirdest of all time.

The fossils, found at a construction site in Carlsbad as workers were getting ready to build hundreds of new homes, are one of the biggest archeological discoveries relating to the Ice Age in a long time. But there have certainly been stranger cases, according to a Discovery Magazine report.

1. Scientists a few years ago discovered ancient sperm dating back 50 million years from a certain type of worm in Antarctica, the oldest ever discovered.

2. Even more bizarre was the discovery of a Silurian shrimp with a 425-million-year-old penis. It was found in a ditch in the early 2000s near the border of England and Wales. This seed shrimp was nicknamed Old Todger and was well-endowed to an extent not usually seen in most creatures.

3. Dinosaur fossils are great, but scientists were super excited after stumbling across dinosaur poo, or “stink rocks,” which began happening in the early 1990s. Petrified dung is important because scientists can determine what the animal was eating.

4. Rhinos in England? It really happened, and we know this thanks to the discovery of a fossil in Kirkdale Cave back in 1821. Workers were quarrying for roadstone when they found large animal bones, and a scientist determined that this was indeed from an ancient rhino that once roamed England.

5. One of the most intriguing fossils ever was first found back in the 19th century in Illinois, and it remained relatively unknown until the 1950s began Mazon Creek became famous for fossils after Francis Tully examined more closely this strange creature: a soft-bodied animal that was set in a naturally split mineral nodule. This specimen was found all over Mazon Creek, but nowhere else. It has two eyes on stalks, a segmented body, a tail with fins, and pincers on one end. Even today, scientists aren’t quite sure what to make of it.