Reconstruction of the oldest sea-going reptile from the Southern Hemisphere. Nothosaurs swimming along the ancient southern polar coast of what is now New Zealand around 246 million years ago.
Artwork by Stavros Kundromichalis.
Sometimes, it must seem as though everything that happened on Earth happened before creationists believe the Universe was created. The simple reason is that this is precisely so, since about 99.9975% of time has existed between when Earth formed out of an accretion disk around the sun and when creationists believe their magic creator god created a universe as a small flat planet with a dome over it in the Middle East, 10,000 years ago.
For example, by about 246 million years ago, life had evolved to the point where terrestrial reptiles were returning to the sea where they evolved into large, marine predators - the apex predators of their day. This means that there was plenty of other life in the seas for them to predate upon, and the fossilised remains of one of them has recently been found in rocks on the southern coast of New Zealand, making it the oldest marine reptile fossil ever found in the southern hemisphere.
Tell me all about the ancient ocean, Panthalassa, from about 246 million years ago, please. Panthalassa, also known as the Panthalassic Ocean, was the vast global ocean that surrounded the supercontinent Pangaea during the late Paleozoic and early Mesozoic eras. About 246 million years ago, during the late Triassic period, Panthalassa played a crucial role in shaping the Earth's climate, marine biodiversity, and tectonic activity.At the time it died, what is now the southern coast of New Zealand formed part of the southern polar coast of a vast ocean called Panthalassa.
Formation and Geography
- Formation:
- Panthalassa formed as a result of the assembly of the supercontinent Pangaea. This massive landmass brought together most of the Earth's continental crust, leaving a single, expansive ocean to cover the rest of the planet.
- It existed from the late Paleozoic era, around 300 million years ago, and persisted until the breakup of Pangaea during the Mesozoic era, which started around 200 million years ago.
- Geography:
- Panthalassa was essentially a global ocean, covering the majority of the Earth's surface. It surrounded Pangaea, which was centered around the equator and stretched towards the poles.
- It included several proto-oceans and marginal seas, such as the Tethys Ocean, which lay to the east of Pangaea and played a crucial role in marine life migration and climate regulation.
Climate and Environmental Impact
- Climate:
- The climate during the Triassic period was generally warm and dry, with minimal ice at the poles. Panthalassa's vast expanse played a significant role in regulating global climate patterns.
- Ocean currents within Panthalassa would have influenced heat distribution, affecting both marine and terrestrial climates on Pangaea.
- Environmental Impact:
- Panthalassa's immense size meant it had a profound impact on the Earth's hydrological cycle, including precipitation and evaporation rates.
- The ocean's chemistry and circulation patterns would have contributed to the distribution of nutrients, supporting marine life.
Marine Life and Biodiversity
- Marine Ecosystems:
- Panthalassa hosted diverse marine ecosystems, from shallow coastal environments to deep oceanic regions. These ecosystems were home to various marine organisms, including early marine reptiles, ammonites, and fish.
- The ocean's vastness provided numerous ecological niches, fostering evolutionary diversification.
- Fossil Record:
- The fossil record from this period shows a rich diversity of marine life. Ammonites, a type of mollusk, are particularly well-represented and serve as important index fossils for dating and correlating geological formations.
- Early marine reptiles, such as ichthyosaurs and nothosaurs, thrived in Panthalassa, indicating the development of complex marine food webs.
Tectonic Activity
- Plate Tectonics:
- Panthalassa's seafloor was dynamic, with active mid-ocean ridges, subduction zones, and volcanic activity. These tectonic processes contributed to the formation of oceanic crust and influenced the ocean's bathymetry.
- The movement of tectonic plates within Panthalassa would eventually lead to the fragmentation of Pangaea, giving rise to the modern oceans.
- Subduction Zones:
- Subduction zones, where oceanic plates descended beneath continental plates, were prominent in Panthalassa. These zones were sites of intense volcanic activity and played a crucial role in recycling oceanic crust.
Geological and Historical Significance
- Historical Context:
- Panthalassa existed during a critical period in Earth's history, encompassing major events such as the Permian-Triassic extinction event, which occurred around 252 million years ago, just before the time frame in question.
- This extinction event was the most severe in Earth's history, wiping out a significant portion of marine and terrestrial species. Panthalassa's ecosystems would have been profoundly affected, with subsequent recovery and diversification occurring during the Triassic period.
- Geological Significance:
- The sedimentary records from Panthalassa provide valuable insights into past oceanographic conditions, climate changes, and biological evolution. These records help scientists reconstruct ancient environments and understand the Earth's geological history.
In summary, Panthalassa was a vast and dynamic ocean that played a pivotal role in Earth's climatic, biological, and geological history around 246 million years ago. Its interactions with the supercontinent Pangaea shaped the environment and life on Earth during the Triassic period, setting the stage for future evolutionary and geological developments.
How the fossil was identified is the subject of an open access paper by an international team led by Dr. Benjamin Kear of the Museum of Evolution, Upsala University, Sweden, in the Cell Press journal, Current Biology and a press release from Upsala University:
An international team of scientists has identified the oldest fossil of a sea-going reptile from the Southern Hemisphere – a nothosaur vertebra found on New Zealand’s South Island. 246 million years ago, at the beginning of the Age of Dinosaurs, New Zealand was located on the southern polar coast of a vast super-ocean called Panthalassa.
Reptiles first invaded the seas after a catastrophic mass extinction that devastated marine ecosystems and paved the way for the dawn of the Age of Dinosaurs almost 252 million years ago. Evidence for this evolutionary milestone has only been discovered in a few places around the world: on the Arctic island of Spitsbergen, northwestern North America and southwestern China. Although represented by just a single vertebra that was excavated from a boulder in a stream bed at the foot of Mount Harper on the South Island of New Zealand – this discovery has shed new light on the previously unknown record of early sea reptiles from the Southern Hemisphere.
Reptiles ruled the seas for millions of years before dinosaurs dominated the land. The most diverse and geologically longest surviving group were the sauropterygians, with an evolutionary history spanning over 180 million years. The group included the long-necked plesiosaurs, which resembled the popular image of the Loch Ness Monster. Nothosaurs were distant predecessors of the Plesiosaurs. They could grow up to seven metres long and swam using four paddle-like limbs. Nothosaurs had flattened skulls with a meshwork of slender conical teeth that were used to catch fish and squid.
The New Zealand nothosaur was discovered during a geological survey in 1978, but its importance was not fully recognised until palaeontologists from Sweden, Norway, New Zealand, Australia and East Timor joined their expertise to examine and analyse the vertebra and other associated fossils.
The nothosaur found in New Zealand is over 40 million years older than the previously oldest known sauropterygian fossils from the Southern Hemisphere. We show that these ancient sea reptiles lived in a shallow coastal environment teeming with marine creatures within what was then the southern polar circle.
Dr Benjamin Kear, lead author
The Museum of Evolution
Uppsala University, Upsala, Sweden.
The oldest nothosaur fossils are around 248 million years old and have been found along an ancient northern low-latitude belt that stretched from the remote northeastern to northwestern margins of the Panthalassa super-ocean. The origin, distribution and timing of when nothosaurs reached these distant areas are still debated. Some theories suggest that they either migrated along northern polar coastlines, or swam through inland seaways, or used currents to cross the Panthalassa super-ocean.
The new nothosaur fossil from New Zealand has now upended these long-standing hypotheses.
Using a time-calibrated evolutionary model of sauropterygian global distributions, we show that nothosaurs originated near the equator, then rapidly spread both northwards and southwards at the same time as complex marine ecosystems became re-established after the cataclysmic mass extinction that marked the beginning of the Age of Dinosaurs. The beginning of the Age of Dinosaurs was characterised by extreme global warming, which allowed these marine reptiles to thrive at the South Pole. This also suggests that the ancient polar regions were a likely route for their earliest global migrations, much like the epic trans-oceanic journeys undertaken by whales today. Undoubtedly, there are more fossil remains of long-extinct sea monsters waiting to be discovered in New Zealand and elsewhere in the Southern Hemisphere.
Dr Benjamin Kear.
The New Zealand nothosaur fossil is held in the National Palaeontological Collection at GNS Science in New Zealand.
Article: Kear, B.P., Roberts, A.J., Young, G., Terezow, M., Mantle, D.J., Barros, I.S. & Hurum, J.H. 2024. Oldest southern sauropterygian reveals early marine reptile globalization. Current Biology 34, R1-R3. DOI: 10.1016/j.cub.2024.03.035
SummaryTraditionally, creationists routinely ignore the supposed commands of their god and simply bear false witness against the scientists who produce this sort of information, variously accusing them of forging the fossils, falsifying the data or using a flawed dating method to give them the date they want, but one thing they can never explain, despite being asked to on multiple occasions, is to explain why the dating method used made 10,000 years or less look like, in this case 246 million years, or in other cases, whatever creationists need it to look like.
Sauropterygians were the stratigraphically longest-ranging clade of Mesozoic marine reptiles with a global fossil record spanning ∼180 million years1. However, their early evolution has only been known from what is now the Northern Hemisphere, extending across the northern and trans-equatorial western margins of the Tethys paleo-ocean1 after the late-Early Triassic (late Olenekian, ∼248.8 million years [Ma] ago2), and via possible trans-Arctic migration1 to the Eastern Panthalassa super-ocean prior to the earliest Middle Triassic (Olenekian–earliest Anisian3,4, ∼247 Ma). Here, we describe the geologically oldest sea-going reptile from the Southern Hemisphere — a nothosaur (basal sauropterygian5) from the Middle Triassic (Anisian, after ∼246 Ma6) of New Zealand. Time-scaled ancestral range estimations thus reveal an unexpected circum-Gondwanan high-paleolatitude (>60° S7) dispersal from a northern Tethyan origination center. This coincides with the adaptive diversification of sauropterygians after the end-Permian mass extinction8 and suggests that rapid globalization accompanied their initial radiation in the earliest Mesozoic.
Main text
The nothosaur fossil (New Zealand National Paleontological Collection, GNS Science [GNS] CD 540: Figures 1A and S1A–D) was recovered from a loose boulder found along the main tributary of Balmacaan Stream at the base of Mt Harper in the Harper Range on central South Island, New Zealand9. The encasing indurated siltstone rock conforms to adjacent strata of the Balmacaan Formation, which has produced a rich macroinvertebrate fauna, including the lophospirid gastropod Mellarium9 that occurs in direct association with GNS CD 540 (Figure S1E) and is age-diagnostic for the lower Etalian stage of the New Zealand Geological Timescale6 (= mid-lower to upper Anisian). We also extracted inertinite (degraded plant material) as the dominant organic component in the adhering siltstone; this accords with abundant woody plant remains and regressive nearshore depositional conditions reported for the Balmacaan Formation9.GNS CD 540 is an isolated posterior-most dorsal vertebra that has been weathered by water transport, destroying the prezygapophyses, leading edge of the neural spine, and anterior articular surface of the centrum. Nonetheless, the well preserved posterior articular surface is flat, indicating an originally platycoelous centrum profile, and together with weakly constricted centrum sides, laterally expanded centrum-neural arch contact, short transverse processes (accommodating most of the dorsal rib facet), and inset zygantrum situated between the shallowly inclined (∼20º) postzygapophyses, denotes morphological compatibility with Eosauropterygia (the clade incorporating pachypleurosaurs, nothosaurs, pistosaurs and plesiosaurs)5. The absence of pachyostotic internal bone structure, accessory infrapostzygapophyses, and the retention of zygosphene–zygantrum articulations differentiates GNS CD 540 from pachypleurosaurs, pistosaurs and plesiosaurs5, respectively. Finally, the large size (maximum vertebral height/centrum diameter = 123.6/53 mm) and tall neural spine with transversely expanded apex are particularly reminiscent of Nothosaurus species described from Middle Triassic (Anisian–Ladinian) Gondwanan shelf deposits in the Middle East5.
Figure 1Morphology and biogeographic context of the oldest Southern Hemisphere sauropterygian.
(A) mCT image of the GNS CD 540 dorsal vertebra in posterior view. (B) Time-scaled8 Bayesian phylogeny (Figure S1G) of Nothosauroidea (silhouettes) with estimated ancestral ranges (pie charts), dispersal (orange circles) and vicariance (blue circles) events (Table S1). Node numbers indicate geographic ranges (red) and percent (>50%) support (black) for ancestral range estimations. (C) Middle Triassic global map showing ancestral ranges (solid arrows) and possible dispersal routes (dashed arrows; modified from maps compiled by Colorado Plateau Geosystems Inc. https://deeptimemaps.com/). (D) Middle Triassic southern polar map with occurrence of GNS CD 540 (red star). Anatomical abbreviations: as, centrum articular surface; le, laterally expanded neural arch contact; ns, neural spine; tp, transverse process; zg, zygantrum; zy, postzygapophysis. Geographic ranges: (1) Northeastern to Northwestern Tethys; (2) Northwestern Tethys to Eastern Panthalassa; (3) Northern Tethys to Southern Polar Panthalassa; (4) Northern Tethys to Southwestern Tethys.
We scored GNS CD 540 into a published tip-dated phylogeny of sauropterygians8 to timescale our ancestral range estimations and reconstruct a dispersal history for the group. These analyses (Supplemental information) unanimously placed GNS CD 540 in the monophyletic clade Nothosauroidea (Figures 1B and S1F,G), comprising nothosaurs with closely related simosaurids and pistosauroids (pistosaurs and plesiosaurs)5. While species-level geographic sampling of the parent dataset is incomplete, we retrieved a robustly supported origination center from the northeastern Tethys (Figure 1C) that coincides with the inferred emergence of nothosauroids around the earliest Triassic8. A subsequent range expansion into the northwestern Tethys accompanied nothosauroid intra-clade divergences across the mid-Early Triassic8, and likely facilitated the southward radiation of nothosaurs (as well as simosaurids, pistosauroids and other sauropterygians5) along the contiguous shallow marine shelf of northern Gondwana during the Middle Triassic5. Significantly, we now also show that nothosaurs achieved an extended extra-Tethyan dispersal circumscribing the entire peninsular landmass of eastern Gondwana to reach the Panthalassan southern polar periphery by at least the early-Middle Triassic (Figure 1D). An opposing southeastern Tethyan migration route (perhaps following island chains to cross open ocean) might have been feasible but contrasts with the restricted coastal habitats assumed for most Triassic sauropterygians1,4,5,10.
In summary, the discovery of GNS CD 540 pushes back the fossil record of Southern Hemisphere sauropterygians by over 40 Ma10, and demonstrates that previously equivocal Austral Triassic occurrences are clearly a result of insufficient sampling10. Furthermore, the unambiguous high-paleolatitude setting of GNS CD 540 counters the proposal that adverse paleoenvironments prevented Triassic sauropterygians from poleward dispersals5, which otherwise explains their unusually disjunct distribution bridging the peri-equatorial northern Tethyan to Eastern Panthalassan oceans1. Indeed, isotopic paleotemperatures provide no indication of cold climate barriers7 hindering marine reptile migrations across Triassic high-paleolatitudes. We therefore expect future exploration to yield more Triassic sauropterygian fossils from the Southern Hemisphere, highlighting the importance of GNS CD 540 as the first evidence of early globalization concurrent with the establishment of complex marine tetrapod ecosystems, and the rise of reptiles as oceanic predators after the end-Permian mass extinction4.
Kear, Benjamin P.; Roberts, Aubrey J.; Young, George; Terezow, Marianna; Mantle, Daniel J.; Barros, Isaias Santos; Hurum, Jørn H.
Oldest southern sauropterygian reveals early marine reptile globalization
Current Biology 34(12) R562-R563. DOI: 10.1016/j.cub.2024.03.035
Copyright: © 2024 The authors.
Published by Elsevier Inc. Open access.
Reprinted under a Creative Commons Attribution 4.0 International license (CC BY 4.0)
In this example, the palaeontologists used the index fossils, Mellarium (a gastropod mollusc) which has previously been dated by the age of the rocks in which it is found, which have themselves been dated using zircons, which give a very accurate date, depending on the decay rates of isotopes of uranium to produce stable isotopes of lead (U-Pb dating). U-Pb dating depends on the known half-life of uranium isotopes which could only change to make 10,000 years look like 246 million years if the weak and strong nuclear forces holding the atomic nucleus together changed so radically that 10,000 years ago, atoms could not have formed, so stars and planets could not have been created, let alone life on Earth, when creationists believe it was created.
I have yet to see a creationist even acknowledge this flaw in their argument, let alone have the courage to address it.
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