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Took this photo of an unnamed eschrichtiid from the Pliocene San Diego Formation of San Diego County in March 2019. Until the 2000s, the fossil record of gray whales was confined to the Pleistocene, but thanks to the work of Michelangelo Bisconti, it is apparent that gray whales emerged about the same time as the oldest rorquals (Eschrichtioides was long considered a balaenopterid, but eventually recognized as a gray whale relative).

Humans in California 130,000 years ago? Bold study says it's possible Humans in California 130,000 years ago? Bold study says it's possible, CBS News, April 26, 2017 http://www.cbsnews.com/news/humans-in-california-130000-years-ago-bold-study-says-its-possible/ Holen, S. R., T. A. Deméré, and others, 2017, A 130,000- year-old archaeological site in southern California, USA Nature 544, 479–483 (27 April 2017) doi:10.1038/nature2206 https://www.nature.com/nature/journal/v544/n7651/full/nature22065.html Yours, Paul H.

Greetings, My lying eyes are struggling with the unlikely chance that the forms in this rock are biological in origin. This looks like coral to me: I see rough impressions of corallites, polyp anatomy, septa, hexagonal and circular chambers, and signs of stacked chambers where masses are sheared perpendicular to the exterior surfaces. The average diameter of the corallite-like openings is ~.5 cm. Many are smaller. Some are up to 2 cm. Note the manner in which various tilted tubes erode to reveal their lengths and interiors; and the presence of angle-cornered walls that group fields of corallite-like forms (LooksLikeCoral1.jpg). The bed from which these blocks and boulders emerged is sandwiched between crystalline limestone, garnet gneiss, and quartzite. These in turn are closely adjacent to a granitic intrusion. The rock shown here is metamorphic. It feels more dense than quartz, and seems at least as hard as quartz, and reacts very weakly with acid. At a broken edge, its separately fractured crystals reveals the nearly transparent vitreous luster, and the color is proportioned ~95% colorless and ~5% olive green. Examples of the most coherent masses of this rock are seen in LooksLikeCoral1.jpg and LooksLikeCoral2.jpg. A less coherent form of the rock includes a comparatively more easily eroded fibrous mineral that separates the tougher corallite-like layers (see LooksLikeCoral3.jpg). This fibrous mineral is composed of crystals which I believe have the same proportion of colorless and olive green. At the site of the rocks, there is a transition from coherent coral textured masses to less coherent: The fibrous fill increases in volume between ever more deeply curved layers of "remaining" hexagonal nuggets which gradually lose their walls. At one margin of the whole site, the fibrous filler is replaced with marble. And at another, where it approaches the granitic intrusion, there is a transition through stages of melt until the nugget layers are obliterated and mixed into a swirling fine grained mass, finally becoming indistinguishable from quartzite. The site is on privately owned land in the San Ysidro Mountain block of Eastern San Diego County, California. Quite some time ago, this block was determined to go back to the Ordovician, but no physical evidence for this claim has been found. I will test specific gravity, and next week, sections from a sample will be cut and polished for a look inside. I will share the results. In the meantime, it would be interesting to discuss: If you didn't know this was metamorphic rock, would you think these textures and patterns have biological origin? In the unlikely event this is fossil material, do the forms and patterns suggest an ID, and period? If you are forced to speculate that this could indeed be fossil material, what tough mineral/s might have first replaced the biological material so that it could survive the heat, pressure and deformation of mountain building? Just as interesting, can you suggest any non-biological processes that would result in forms and patterns like these? Thanks in advance for replies.