Mark McMenamin

Last updated
Mark McMenamin
Born1957or1958(age 65–66) [1]
Oregon, U.S.
Citizenship United States
Alma mater University of California, Santa Barbara, Ph.D.
Stanford University, B.S.
Known forEdiacaran fossils; Hypersea theory; Proterozoic supercontinent Rodinia [2]
SpouseDianna L. Schulte McMenamin
Awards Presidential Young Investigator Award
Sigma Xi National Lecturer
2011 Irish Education 100 Award [2] [3]
Scientific career
Fields Paleontology, Geology
Institutions Mount Holyoke College [2]

Mark A. S. McMenamin (born c. 1957) is an American paleontologist and professor of geology at Mount Holyoke College. He has contributed to the study of the Cambrian explosion and the Ediacaran biota.

Contents

He is the author of several books, most recently Deep Time Analysis (2018) and Dynamic Paleontology (2016). His earlier works include The Garden of Ediacara: Discovering the Earliest Complex Life (1998), one of the only popular accounts of research on the Ediacaran biota, and Science 101: Geology (2007). He is credited with co-naming several geological formations in Mexico, describing several new fossil genera and species, and naming the Precambrian supercontinent Rodinia [4] and the superocean Mirovia. [5] [6] The Cambrian archeocyathid species Markocyathus clementensis was named in his honor in 1989. [7]

Early life and career

McMenamin was born in Oregon, [1] earned his B.S. at Stanford University in 1979 and his PhD at the University of California, Santa Barbara in 1984. [8] In 1980, while at Santa Barbara he met his future wife, Dianna, also a paleontology graduate student, with whom he would co-author several publications. He joined the staff at Mount Holyoke College in 1984. [9] In October 2021, he described a Jurassic-period dinosaur fossil in South Hadley, Massachusetts. [10]

Origins of complex life

In 1995 McMenamin led a field expedition to Sonora, Mexico, that discovered fossils (550-560 million years old [11] ) which McMenamin argued belonged to a diverse community of early animals and Ediacaran biota. [12] The paper was published in the Proceedings of the National Academy of Sciences of the United States of America where it was reviewed by Ediacaran expert James G. Gehling. In 2011, McMenamin reported the discovery of the oldest known adult animal fossils, Proterozoic chitons from the Clemente Formation, northwestern Sonora, Mexico. [13] [14] [11] Further up in this same stratigraphic sequence, McMenamin also discovered and named the early shelly fossil Sinotubulites cienegensis, a fossil that allowed the first confident Proterozoic biostratigraphic correlation between Asia and the Americas. [15] In Lower Cambrian strata higher in the stratigraphic sequence, McMenamin also discovered important stem group brachiopods belonging to the genus Mickwitzia. [16] During a Mount Holyoke College field trip to Death Valley, California, McMenamin and his co-authors found evidence indicating that the Proterozoic shelly fossil Qinella survived the Proterozoic-Cambrian boundary. [17] [14]

In 2012 McMenamin proposed that the enigmatic Cambrian trace fossil Paleodictyon was the nest of an unknown animal, a hypothesis which, if supported, may be the earliest fossil evidence of parental behavior, surpassing previous findings by 200 million years. [18] In his 2019 article 'Cambrian Chordates and Vetulicolians', McMenamin described Shenzianyuloma yunnanense, a new genus and species of Vetulicolia interpreted as bearing myotome cones, a notochord, and gut diverticula in its posterior section. [19]

Hypersea

In an attempt to explain the unprecedented and rapid spread of vegetation over dry land surfaces during the middle Paleozoic, Mark and Dianna McMenamin proposed the Hypersea Theory. [9] Their Hypersea is a geophysiological entity consisting of eukaryotic organisms on land and their symbionts. By means of a process known as hypermarine upwelling, the expansion of Hypersea led to a dramatic increase in global species diversity and a one hundred-fold increase in global biomass. [20] [21] Mark McMenamin's Hypertopia Option has been called one of only two "means by which planetary temperature can be stabilized." [22]

Critique of Neodarwinism

Mark McMenamin has repeatedly criticized conventional Neodarwinian theory as inadequate to the task of explaining the evolutionary process. Joining with Lynn Margulis and the Russian symbiogeneticists, McMenamin has argued that symbiogenesis theory is important as one means of addressing the gap in our understanding of macroevolutionary change in conventional Neodarwinian terms. [23]

Phoenician coins

In 1996, McMenamin proposed that Phoenician sailors discovered the New World c. 350 BC. [24] The Phoenician state of Carthage minted gold staters in 350 BC bearing a pattern in the reverse exergue of the coins, which McMenamin interpreted as a map of the Mediterranean with the Americas shown to the west across the Atlantic. [24] [25] McMenamin later demonstrated that other (base metal) coins found in America were modern forgeries. [26]

Triassic kraken

Mark McMenamin and Dianna Schulte McMenamin argued that a formation of multiple ichthyosaur fossils (belonging to the genus Shonisaurus ) placed together at Berlin–Ichthyosaur State Park may represent evidence of a gigantic cephalopod or Triassic kraken that killed the ichthyosaurs and intentionally arranged their bones in the unusual pattern seen at the site. [27] [28]

Opponents have challenged the theory as too far-fetched to be credible. [29] [30] PZ Myers believes that a much simpler explanation is that the rows of vertebral discs may be a result of the ichthyosaurs having fallen to one side or the other after death and rotting in that position, while Ryosuke Motani, a paleontologist at the University of California, Davis, has alternately proposed that the bones may have been moved together by ocean currents because of their circular shape. [31] McMenamin has dismissed both of these concerns as not being in accord with either the sequence of bone placement or the hydrodynamics of the site. [32]

Mark and Dianna McMenamin presented new evidence favoring the existence of the hypothesized Triassic kraken on October 31, 2013 at the Geological Society of America annual meeting in Denver, Colorado. [33] Paleontologist David Fastovsky critiqued McMenamin's argument, saying that the fossil fragment used as evidence was too small to determine its origin and that the argument about currents didn't take into account the lack of knowledge about currents at the time and what would be needed to move the vertebrae. Fastovsky stated that the most likely scenario was one in which, once the tendons and ligaments holding the vertebrae together are gone, the vertebral column "sort of starts to fall over almost like a row of dominoes" with the most likely configuration for that to be the assemblage found. [34] Adolf Seilacher has noted that this ichthyosaur bone arrangement "has never been observed at other localities". [35]

In 2023, McMenamin described a fossil that he interpreted as upper beak rostrum of a large cephalopod and estimated total length of this animal at 28.6 metres (94 ft). Based on the morphology of the fossil, McMenamin rejected previous interpretation of the fossil as part of the hinge of a ramonalinid clam. [36]

Filmography

Film and television
YearTitleRoleNotes
2006Naked Science--Colliding ContinentsMiscellaneous Crew, HimselfNational Geographic
2007 How the Earth Was Made HimselfHistory Channel
2013 America Unearthed HimselfCommittee Films TV Documentary

Books

Related Research Articles

<span class="mw-page-title-main">Ediacaran</span> Third and last period of the Neoproterozoic Era

The Ediacaran period is a geological period of the Neoproterozoic era that spans 96 million years from the end of the Cryogenian period at 635 Mya, to the beginning of the Cambrian period at 538.8 Mya. It is the last period of the Proterozoic eon as well as the last of the so-called "Precambrian supereon", before the beginning of the subsequent Cambrian period marks the start of the Phanerozoic eon where recognizable fossil evidence of life becomes common.

The PaleozoicEra is the first of three geological eras of the Phanerozoic Eon. Beginning 538.8 million years ago (Ma), it succeeds the Neoproterozoic and ends 251.9 Ma at the start of the Mesozoic Era. The Paleozoic is subdivided into six geologic periods :

The Precambrian is the earliest part of Earth's history, set before the current Phanerozoic Eon. The Precambrian is so named because it preceded the Cambrian, the first period of the Phanerozoic Eon, which is named after Cambria, the Latinised name for Wales, where rocks from this age were first studied. The Precambrian accounts for 88% of the Earth's geologic time.

<span class="mw-page-title-main">Proterozoic</span> Geologic eon, 2500–539 million years ago

The Proterozoic is the third of the four geologic eons of Earth's history, spanning the time interval from 2500 to 538.8 Mya, the longest eon of the Earth's geologic time scale. It is preceded by the Archean and followed by the Phanerozoic, and is the most recent part of the Precambrian "supereon".

<i>Treptichnus</i> Preserved burrow of an animal

Treptichnus is the preserved burrow of an animal. As such, it is regarded as the earliest widespread complex trace fossil. Its earliest appearance, around 542 mya, which was contemporaneous with the last of the Ediacaran biota, is used to help define the dividing line, considered geologically at 541 mya, between the Ediacaran and Cambrian periods. It is last seen in the fossil record during the Cenomanian.

<span class="mw-page-title-main">Superocean</span> Ocean that surrounds a supercontinent

A superocean is an ocean that surrounds a supercontinent. It is less commonly defined as any ocean larger than the current Pacific Ocean. Named global superoceans include Mirovia, which surrounded the supercontinent Rodinia, and Panthalassa, which surrounded the supercontinent Pangaea. Pannotia and Columbia, along with landmasses before Columbia, were also surrounded by superoceans.

<span class="mw-page-title-main">Vendobionta</span> Group of extinct creatures that were part of the Ediacaran biota

Vendobionts or Vendozoans (Vendobionta) are a proposed very high-level, extinct clade of benthic organisms that made up of the majority of the organisms that were part of the Ediacaran biota. It is a hypothetical group and at the same time, it would be the oldest of the animals that populated the Earth about 580 million years ago, in the Ediacaran period. They became extinct shortly after the so-called Cambrian explosion, with the introduction of fauna formed by more recognizable groups and more related to modern animals. It is very likely that the whole Ediacaran biota is not a monophyletic clade and not every genus placed in its subtaxa is an animal.

<i>Swartpuntia</i> Extinct genus of Ediacaran fossil

Swartpuntia is a monospecific genus of erniettomorph from the terminal Ediacaran period, with at least three quilted, leaf-shaped petaloids — probably five or six. The petaloids comprise vertical sheets of tubes filled with sand. Swartpuntia specimens range in length from 12 to 19 cm, and in width from 11.5 to 140 cm. The margin is serrated, with a 1 mm wide groove. A 14 mm wide stem extends down the middle, tapering towards the top, and stopping 25 mm from the tip. The stem has a V-shaped ornamentation on it. The original fossils were found at, and named after, the Swartpunt farm between Aus and Rosh Pinah in Namibia. The generic name comes from Swartpunt, meaning black point in reference to the colour of the rocks. The specific name germsi honours Gerard Germs, who studied the Nama formation of geological beds.

<span class="mw-page-title-main">Ediacaran biota</span> All organisms of the Ediacaran Period (c. 635–538.8 million years ago)

The Ediacaranbiota is a taxonomic period classification that consists of all life forms that were present on Earth during the Ediacaran Period. These were enigmatic tubular and frond-shaped, mostly sessile, organisms. Trace fossils of these organisms have been found worldwide, and represent the earliest known complex multicellular organisms. The term "Ediacara biota" has received criticism from some scientists due to its alleged inconsistency, arbitrary exclusion of certain fossils, and inability to be precisely defined.

Laudonia is an extinct genus of trilobites that lived during the early part of the Botomian stage, which lasted from approximately 524 to 518.5 million years ago. This faunal stage was part of the Cambrian Period. There are currently two named species assigned to it.

The small shelly fauna, small shelly fossils (SSF), or early skeletal fossils (ESF) are mineralized fossils, many only a few millimetres long, with a nearly continuous record from the latest stages of the Ediacaran to the end of the Early Cambrian Period. They are very diverse, and there is no formal definition of "small shelly fauna" or "small shelly fossils". Almost all are from earlier rocks than more familiar fossils such as trilobites. Since most SSFs were preserved by being covered quickly with phosphate and this method of preservation is mainly limited to the late Ediacaran and early Cambrian periods, the animals that made them may actually have arisen earlier and persisted after this time span.

The Cambrian explosion, Cambrian radiation,Cambrian diversification, or the Biological Big Bang refers to an interval of time approximately 538.8 million years ago in the Cambrian Period of early Paleozoic when there was a sudden radiation of complex life and practically all major animal phyla started appearing in the fossil record. It lasted for about 13 – 25 million years and resulted in the divergence of most modern metazoan phyla. The event was accompanied by major diversification in other groups of organisms as well.

<span class="mw-page-title-main">Paleontology in Nevada</span>

Paleontology in Nevada refers to paleontological research occurring within or conducted by people from the U.S. state of Nevada. Nevada has a rich fossil record of plants and animal life spanning the past 650 million years of time. The earliest fossils from the state are from Esmeralda County, and are Late Proterozoic in age and represent stromatolite reefs of cyanobacteria, amongst these reefs were some of the oldest known shells in the fossil record, the Cloudina-fauna. Much of the Proterozoic and Paleozoic fossil story of Nevada is that of a warm, shallow, tropical sea, with a few exceptions towards the Late Paleozoic. As such many fossils across the state are those of marine animals, such as trilobites, brachiopods, bryozoans, honeycomb corals, archaeocyaths, and horn corals.

The Buelna Formation is a geological formation in Mexico. It preserves fossils dating back to the Cambrian period.

The Puerto Blanco Formation is a geologic formation in Mexico. It preserves fossils dating back to the Cambrian period.

The La Ciénega Formation is a geologic formation in Mexico. It preserves fossils dating back to the Carboniferous period.

The Clemente Formation is a geologic formation in Mexico. It preserves fossils dating back to the Ediacaran period.

The Gamuza Formation is a geologic formation in Mexico. It preserves fossils dating back to the Ediacaran period.

The Papalote Formation is a geologic formation in Mexico. It preserves fossils dating back to the Ediacaran period.

References

  1. 1 2 Macone, Steve (June 3, 2007). "Out there". The Boston Globe.
  2. 1 2 3 "Mark McMenamin Faculty Profile". Mount Holyoke College. Retrieved 2011-10-11.
  3. ↑ McGoldrick, Debbie, ed. (2011). "Mark McMenamin". The Irish Voice Third Annual Irish Education 100 Special Supplement: S38.
  4. ↑ Meert, J. G.; Powell, C. M. (2001). "Assembly and breakup of Rodinia". Precambrian Research. 110 (1–4): 1–8. Bibcode:2001PreR..110....1M. doi:10.1016/s0301-9268(01)00177-2.
  5. ↑ McMenamin, Mark A.; McMenamin, Dianna L. (1990). "The Rifting of Rodinia" . The Emergence of Animals. Columbia University Press. ISBN   978-0-231-06647-1.
  6. ↑ Dutkiewicz, A.; Merdith, A. S.; Collins, A. S.; Mather, B.; Ilano, L.; Zahirovic, S.; Dietmar Müller, R. (2024). "Duration of Sturtian 'Snowball Earth' glaciation linked to exceptionally low mid-ocean ridge outgassing". Geology.
  7. ↑ Debrenne, F.; Gandin, A.; Rowland, S. M. (1989). "Lower Cambrian bioconstructions in Northwest Mexico (Sonora). Depositional setting, paleoecology and systematics of archaeocyaths". Geobios. 22 (2): 137–195. Bibcode:1989Geobi..22..137D. doi:10.1016/s0016-6995(89)80127-5.
  8. ↑ "Mark McMenamin Professor of Geology". Mount Holyoke College Geology Department. Retrieved 2015-02-04.
  9. 1 2 Zimmer, Carl (October 1995). "Hypersea Invasion". Discover Magazine.
  10. ↑ "Mount Holyoke College professor discovers a local dinosaur bone". New England Public Media. 2022-02-21. Retrieved 2022-02-22.
  11. 1 2 McMenamin, Mark A. S. (2018). Deep Time Analysis: A Coherent View of the History of Life. Springer. ISBN   978-3-319-74255-7.
  12. ↑ McMenamin, M. A. S. (1996). "Ediacaran biota from Sonora, Mexico". Proceedings of the National Academy of Sciences of the United States of America. 93 (10): 4990–4993. Bibcode:1996PNAS...93.4990M. doi: 10.1073/pnas.93.10.4990 . PMC   39393 . PMID   11607679.
  13. ↑ McMenamin, M. A. S. (2011). "Fossil chitons and Monomorphichnus from the Ediacaran Clemente Formation, Sonora, Mexico". Geological Society of America Abstracts with Programs. 43 (5): 87.
  14. 1 2 McMenamin, Mark A. S. (2016). Dynamic Paleontology: Using Quantification and Other Tools to Decipher the History of Life. Springer. ISBN   978-3-319-22776-4.
  15. ↑ McMenamin, M. A. S. (1985). "Basal Cambrian small shelly fossils from the La Ciénega Formation, northwestern Sonora, Mexico". Journal of Paleontology. 59 (6): 1414–1425.
  16. ↑ McMenamin, M. A. S. (1992). "Two new species of the Cambrian genus Mickwitzia". Journal of Paleontology. 66 (2): 173–182. Bibcode:1992JPal...66..173M. doi:10.1017/S0022336000033680. S2CID   132405917.
  17. ↑ McMenamin, M. A. S.; Hughes, W. A.; McMenamin, J. M. (2013). "Surviving the Cambrian Explosion: Qinella from Death Valley, California". Geological Society of America Abstracts with Programs. 45 (7): 112.
  18. ↑ Barras, Colin (16 November 2012). "Leonardo fossil sketch may depict early nests". Nature. doi:10.1038/nature.2012.11841. S2CID   191382775.
  19. ↑ McMenamin, Mark A. S. (11 August 2019). "Cambrian Chordates and Vetulicolians". Geosciences. 9 (8): 354. Bibcode:2019Geosc...9..354M. doi: 10.3390/geosciences9080354 .
  20. ↑ McMenamin, M. A. S.; McMenamin, D. L. S. (1993). "Hypersea and the land ecosystem". BioSystems. 31 (2–3): 145–153. doi:10.1016/0303-2647(93)90043-c. PMID   8155847.
  21. ↑ McMenamin, M. A. S.; McMenamin, D. L. S. (1994). Hypersea: Life on the Land. Columbia University Press. ISBN   0-231-07530-8.
  22. ↑ McPherson, G. R.; Sirmacek, Beril Kallfelz; Massa, J. R.; Kallfelz, W.; Vinuesa, R. (2023). "The commonly overlooked environmental tipping points". Results in Engineering. 18: 101118. doi: 10.1016/j.rineng.2023.101118 . S2CID   258399831.
  23. ↑ Margulis, L.; McMenamin, M. A. S. (1990). "Kinetosome-centriolar DNA: Significance for endosymbiosis theory". Treballs de la Societat Catalana de Biologia. 41: 5–16.
  24. 1 2 Scott, J. M. 2005. Geography in Early Judaism and Christianity. Cambridge University Press, pp. 182–183.
  25. ↑ McMenamin, M. A. 1997. The Phoenician World Map. Mercator's World 2(3): 46–51.
  26. ↑ McMenamin, Mark A. (2000). Phoenicians, Fakes and Barry Fell: Solving the Mystery of Carthaginian Coins Found in America. Meanma Press. p. 22. ISBN   978-1-893882-01-0 . Retrieved 8 February 2020. The putative Carthaginian coins must now be removed from the body admissible evidence favoring a pre-Columbian transatlantic crossing. It gives me some chagrin to admit this, as I had earlier come out mildly in support of the authenticity of these coins (McMenamin 1999b, 2000a, 2000b). Weak evidence (involving measurements of die axis; the Arkansas coin has a die axis [33 degrees] differing from the Alabama type coins [12 to 20 degrees]) in support of the authenticity of these coins (McMenamin 2000b) is superseeded by the strong evidence in the current work.
  27. ↑ McMenamin, Mark A. S.; McMenamin, Dianna Schulte (Oct 2011). "Triassic Kraken: The Berlin Ichthyosaur Death Assemblage Interpreted as a Giant Cephalopod Midden". Geological Society of America Abstracts with Programs. 43 (5): 310.
  28. ↑ "Psycho kraken made portraits from bones of prehistoric whale victims. Maybe..." Herald Sun . The Herald and Weekly Times. October 12, 2011.
  29. ↑ Simpson, Sarah (October 11, 2011). "Smokin' Kraken?". Discovery News. Discovery Channel . Retrieved 2011-10-11.
  30. ↑ "Mythical Kraken-Like Sea Monster Might be Real: Researcher". International Business Times . The International Business Times Inc. October 12, 2011. Retrieved 2011-10-12.
  31. ↑ Than, Ker (October 11, 2011). "Kraken Sea Monster Account "Bizarre and Miraculous"". National Geographic News. National Geographic Society. Archived from the original on October 12, 2011. Retrieved 2011-10-12.
  32. ↑ Flatow, Ira (October 14, 2011). "Seeing a Cephalopod in Ancient Bones". NPR Stories. National Public Radio . Retrieved 2011-10-18.
  33. ↑ McMenamin, M. A. S.; McMenamin, Dianna Schulte (2013). "The Kraken's back: New evidence regarding possible cephalopod arrangement of ichthyosaur skeletons". Geological Society of America Abstracts with Programs. 43 (5): 87.
  34. ↑ Pappas, Stephanie (October 31, 2013). "The kraken rises! New fossil evidence revives sea monster debate". NBC News Science. Retrieved 2012-11-09.
  35. ↑ McMenamin, M. A. S. (2012). "Evidence for a Triassic Kraken: Unusual arrangement of bones at Ichthyosaur State Park in Nevada". 21st Century Science and Technology. 24 (4): 55–58.
  36. ↑ McMenamin, Mark A. S. (2023). "A Late Triassic Nuculanoid Clam (Bivalvia: Nuculanoidea) and Associated Mollusks: Implications for Luning Formation (Nevada, USA) Paleobathymetry". Geosciences. 13 (3): 80. doi: 10.3390/geosciences13030080 . ISSN   2076-3263.
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