{'fraction_non_alphanumeric': 0.023626373626373626, 'fraction_numerical': 0.0, 'mean_word_length': 5.07, '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}}
Benthic-pelagic coupling in Pliocene ocean: Geochemical and micropaleontologic evidence in the ichnofossil Phymatoderma

Numerous studies have revealed the evidence of benthic-pelagic coupling in various ocean areas. In terms of marine benthos, it is well known that feeding, growth and reproduction are generally synchronized with the seasonal input of phytodetritus to the sea-ﬂoor. However, compared to examples of modern organisms, little is known about the evidence of the ancient benthic-pelagic coupling. Thus, the present study carried out the geochemical and microscopic analyses of the fecal pellet-ﬁlled ichnofossil P hy m a t od e r m a from the Pliocene deep-sea strata. The aim of this study is to assess whether benthic-pelagic coupling functioned in the ancient ocean, with special attention to the temporal relationship between phytodetritus input and deposit feeding by the trace-maker. Elemental analysis revealed that Ca, which is probably derived from the calcareous microfossils, is signiﬁcantly accumulated in the tuffaceous pellets. Because the CaO content of the pelletal inﬁll are generally similar to that of the host siltstones, it may be concluded that the recognized Ca accumulation in pellets does not reﬂect diagenetic alteration. SEM ob-servations showed the presence of various types of microfossils (i.e., coccoliths, diatoms, planktonic foraminifera, radiolaria) within the pelletal inﬁll of P hy m a t od e r m a . In addition, excreted tuffaceous fecal pellets are occasionally found to be composed exclusively of coccoliths. Considering all these lines of evidence, it is most likely that the deposit-feeding by the P hy m a t od e r m a producer was synchronized with an episodic (probably seasonal) coccolithophore bloom deposition on the deep-sea ﬂoor. The reconstructed feeding