17 Paleoceanography and paleoclimate of the Gulf of California and how they resonate with the evolution of other marginal seas
This session features studies on the climatic and marine history of the Gulf of California and its connections to the global climate and ocean system, utilizing multidisciplinary geological, micropaleontological, geochemical, and numerical modeling proxies.
Thursday, 23 April 2026
9:30 AM - 12:00 PM
LMH, Deli
The Missing Fossil Record
Paper number: 17-9
Program: Technical Sessions
Time: 11:35 AM – 11:50 AM
Authors
Abstract
In layered sedimentary rocks, fossils seldom occur in every stratigraphic sample due to biological, geological or human factors. The missing fossils can often indicate significant events. That record fails to recover all the information about event timing due to the absence of specimens of critical species in the fossil record of the event. These occurrences or absences in the rock record are not random but are controlled by determinative factors that can reveal much about the history and events of the sequence.
The occurrences or absences in the rock record are not random, as these are controlled by• determinative conditions. For example, punctuated evolutionary events appear sudden because • specimens showing the development of new species are absent from the fossil record and extinctions may appear gradual because species recorded as ranges based on last occurrences may-be erroneous (Signor-Lipps Effect) These imperfections in the fossil record are caused by biological, geological and human factors. Biological factors include those that affect the presence of specimens before or at the time of deposition. -Geological-factors work on the specimens and sediment during and after deposition to eliminate fossil species from the record. Human factors include failure in the collection and processing of the samples.
When the absences are compared with presences, macroecology and paleobiology (biodiversity, associations, species interactions, ecologic interactions, and extinctions & radiations) •and • evolution (biodiversity, population structure & dynamics, extinction dynamics and radiation of• new-biotas) may-be more completely interpreted. Consideration of these missing biotas results in better evidence, better hypotheses and happier scientists.
Geological Society of America Abstracts with Programs. Vol. 58, No. 3
doi: 10.1130/abs/2026CD-411066
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