{'fraction_non_alphanumeric': 0.015789473684210527, 'fraction_numerical': 0.005263157894736842, 'mean_word_length': 4.8538461538461535, 'pattern_counts': {'":': 0, '<': 0, '<?xml version=': 0, '>': 0, 'https://': 0, 'lorem ipsum': 0, 'www.': 0, 'xml': 0}, 'pii_count': 0, 'substrings_counts': 0, 'word_list_counts': {'cursed_substrings.json': 0, 'profanity_word_list.json': 0, 'sexual_word_list.json': 0, 'zh_pornsignals.json': 0}}
Report on the Discovery of Fossil Mares with Preserved Uteroplacenta from the Eocene of Germany

Abstract I report on the discoveries of three pregnant mares from the middle Eocene of Germany that contain remains of fetuses still wrapped in the fossilized uteroplacenta. These are the first and up to now only discoveries of this kind. One specimen comes from the Eckfeld Maar (Eifel Mountains). It is 44 million years of age. The other two were discovered at Grube Messel and are 48 million years old. These are the oldest fossil uteroplacentae known so far. Their morphology corresponds to recent homologues. Presumably, the uteroplacenta developed as part of the propagation system of mammals during the Palaeocene, perhaps already during the late Mesozoic.