Crassostrea oysters. The Miocene shells were obtained from two different locations in California, the Pleistocene shells from Virginia, and the Recent shells from North Carolina. All shells were collected from a relatively narrow latitude band between 34.6° and 36.8° north latitude. The Miocene oysters apparently had much greater maximum lifespans and sizes than the Late Pleistocene and Recent Crassostrea oysters (Figs. 8 and 9). In agreement with Holt (1996), Baumgardner (Oard 2002), Oard (2013), and Clarey (2019), I am assuming that, generally speaking, Miocene and Pleistocene strata are Flood and post-Flood strata, respectively. The dramatic decrease in maximum oyster lifespan shown in Figure 8 parallels the dramatic decrease in human lifespan after the Flood described in Genesis 11. Similar late Cenozoic trends appear in giant clams from the Red Sea region (Killam et al. 2021), Mercenaria clams from North Carolina and Florida (Palmer et al. 2021), and venerid bivalves from the Japanese Islands (Sato 1999). These examples are not as dramatic as those shown in Figures 8 and 9 are are perhaps more easily dismissed. Moreover, the pattern is equivocal for chionine bivalves from the tropical Americas (Roopnarine 1996). These examples are not as dramatic as those shown in Figures 8 and 9 and are perhaps more easily dismissed. Moreover, the pattern does not hold for Mercenaria clams from Florida (Palmer et al. 2021). However, strong evidence for greater mollusc longevity in the preFlood world comes from Seymour Island, Antarctica. A study of 12 Eocene Cucullaea raea shallow-marine clam shells showed “extreme” longevity (Buick and Ivany 2004). Despite the small sample size and the fact that the sample shells were not exceptional in size or number of visible bands, all twelve clams were estimated to be at least 50 years old at time of death, with 6 clams more than 90 years old, and 5 clams greater than 100 years old! Buick and Ivany (2004, p. 922) noted, “These are some of the longest-lived clams ever documented from the modern or ancient world.” A larger study showed that 11 species of Cretaceous and Paleogene Seymour Island bivalves were slow-growing and long-lived (Moss et al. 2017, p. 373): While a number of modern taxa can attain life spans in excess of 50 years, the modal value of maximum reported life span for bivalve species today is 3 years (Moss et al. 2016). The shortest-lived species measured from Seymour Island reached life spans of at least 22 years. The longevity of bivalves in this assemblage, even as established from such a restricted sample, is impressive. Moss et al. (2017) noted that different taxonomic groups were well-represented in their study, as they studied fossil assemblages belonging to three different families in three different orders. Moreover, they noted they were likely underestimating the ages of these bivalve species due to ring counting difficulties and the relatively small sample sizes of their specimens. Even so, they concluded (Moss et al. 2017, p. 365) that “all 11 species examined are both slow growing and long-lived, especially when compared with modern bivalves in similar temperature settings.” Temperature is indeed an important factor in these kinds of studies. Although extant high latitude marine bivalves can live hundreds of years (Abele et al. 2008), this seems to be a temperature-dependent phenomenon, possibly due to a dramatic slowdown in metabolism triggered by extremely cold temperatures. The longevities of these Seymour Island bivalves are particularly impressive because uniformitarians believe the Antarctic Peninsula experienced relatively warm temperatures during the Cretaceous and Paleogene. And most creationists would probably agree that global temperatures in the pre-Flood world were higher than today’s averages. Hence, neither we nor they can use cold temperatures as an explanation for why these particular molluscs lived so long. If anything, such warm temperatures should have sped up their metabolisms, decreasing their longevity. Yet this was not the case. 3. Slowly-maturing birds Apparently, there is osteo-histological evidence that birds once took longer to mature than they do today. A detailed discussion of osteo-histology is beyond the scope of this paper, but we note in passFigure 8. Maximum lifespan (red dots) for four assemblages of California, Virginia, and North Carolina Crassostrea oysters all collected between 34.6° and 36.8° north latitude. The maximum lifespans for the Late Pleistocene and Recent oysters are dramatically less than the maximum life-spans for the Miocene oysters. Black dots represent the average age of each assemblage, and error bars are the standard deviations. The number of fossil specimens in each assemblage is shown. Figure 9. Height-versus-age growth curves constructed for the four Crassostrea oyster assemblages whose data are summarized in Figure 8. After Figure 3B in Kirby (2001). HEBERT Allometric and metabolic scaling 2023 ICC 216
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