‘Oldest snake’ fossils found
Evolution? the fossils still say no!
Published: 1 March 2015 (GMT+10)
Several fossils of snakes (suborder Ophidia) have been discovered in recent decades, but none offered much comfort to those trying to solve the evolutionary puzzle of snake origins. Until now, the oldest fossil snakes have generally been given as around 100 million years. A new paper in Nature Communications, by University of Alberta palaeontologist, Professor Michael Caldwell and colleagues, describes fossils of four species of snakes which, they say, pushes their fossil record back by a whopping ~70 million years.1 In evolutionary thinking, this makes some snakes contemporary with dinosaurs of the middle-Jurassic. In order of their evolutionary ‘age’, they are:
- Parviraptor estesi (from Dorset, England)—145–140 million years
- Diablophis gilmorei (from Colorado, USA)—155 million years
- Portugalophis lignites (from Guimarota, Portugal)—157–152 million years
- Eophis underwoodi (from Oxfordshire, England)—167 million years
The more complete a fossil, the less wiggle-room there is for speculation. Reuters published artistic renditions of the first three of the snakes listed above, picked up by media outlets globally.2 These clearly show small legs on Diablophis gilmorei (see Figure 1) but not on the others*—and a careful reading of the paper confirms that, indeed, no pectoral pelvic or limb bones were found in those species. However, the systematic description of the skeletal and dental specimens for Diablophis gilmorei does not list any such structures for this species either, for instance, as well as the missing pelvis, there are just some precloacal vertebrae and ‘one possible sacral vertebra’. The addition of tiny limbs in the media image is, therefore, entirely unjustifiable; it will mislead all who have not taken time to read the paper for themselves. In actual fact, the skeletons of these snakes are acknowledged to be very incomplete,3 the authors admitting, “we cannot ascertain the shape, length, form and so on of any aspect of the body of the earliest snakes (~167 Myr ago) reported herein” (my emphasis). Nevertheless, as reported, “the researchers say all four may have had some form of reduced forelimbs and hind limbs”.2 Snake limbs will be discussed here later, but it illustrates the strong tendency for evolutionists to go out on a limb with their conjectures (pun intended).
Similarly, Portugalis lignites is pictured as a colourful tree-climber, though based merely on some fragmentary jaw remains (see Figure 3). Interestingly, the authors state that the skull anatomy of all four of these ‘ancient’ snakes is similar to that of modern snakes (and other fossil snakes).4
New insights and a new story?
As is frequently the case with press hype surrounding the field of paleoanthropology—with the perennial ‘ape-man’ claims—this publication has excited the news makers. The writer for Reuters exclaims, “The remarkable fossils … rewrite the history of snake evolution”.2 The paper’s authors are a little more cautious; nevertheless, the title of their paper does claim that these new fossils “provide insights on snake evolution”.1 However, whenever fragmentary fossil evidence is said to ‘rewrite the story’ of evolution, it’s confirmation of just how flimsy the case was in the first place. In like manner, many reports of new hominid (‘ape-man’) claims have been accompanied by media fanfare and the mantra that this ‘could rewrite the story of human evolution’.
A previous article describes the two competing hypotheses regarding the evolution of snakes, so the reader is encouraged to read that first. Briefly, some researchers have held the view that snakes are relatives of monitor lizards which, in turn, are believed to be descended from mosasaurs (aquatic origins). Others prefer a terrestrial origin where various land lizards are the serpents’ ancestors (a terrestrial origin). Proponents of each idea give sound scientific reasons why the opposing view is scientifically untenable, though the terrestrial origin is perhaps the more popular.
It is true that, according to the fossil record, some snakes possessed a pelvic girdle and small hind limbs—though never front limbs or any trace of a pectoral girdle, contrary to the unfounded speculations of Caldwell and colleagues. We have previously discussed such ‘leggy snakes’ here and here. These structures may seem rudimentary to us but that this is evidence for snake limb evolution is far from convincing. They are certainly not functionless. In fact, in certain living species, muscles are anchored to the pelvic girdle and the hind limbs seem to play a role in mating. While there is some debate, anal spurs (either side of the cloaca5) are generally seen as the tips of the hind limbs, and males have been observed using them to arouse females during copulation.6 In other cases, the spurs have apparently been employed in sparring between snakes.7 The idea, therefore, that such hind limbs are vestigial in the traditional evolutionary sense (without function) fails.
In an attempt to rehabilitate vestigial structures as evidence for evolution, some people (such as evolutionary protagonist Jerry Coyne) have attempted to redefine things; a structure can be vestigial and functional at the same time, they claim, just so long as it’s not performing the function for which it originally arose. This tacit admission of the failure of the original vestiges concept has been discussed elsewhere. Without hard evidence that a claimed vestigial structure once performed a wholly different role, it merely begs the question.
However, it would not be that remarkable if one or more living types of snake were shown to once have possessed legs for walking. There exist several living families of lizards in which legs are small or absent. The loss of legs (gradually or quickly) in lizards or snakes would no more pose a challenge to biblical biology than would the loss of functional wings in flightless insects and flightless birds, or of eyes in blind cave fish. In fact, it is quite possible that morphological change in one kind of snake occurred as part of the Divine Curse (Genesis 3:14), while others were created entirely legless from the start, as discussed elsewhere.
Gaps in the snake fossil record
There are numerous scientific evidences for a young age of the earth and the universe, not to mention that the New Testament writers and Jesus believed in a young world. Therefore, there is ample reason to reject the evolutionary dates assigned to the fossils. Nevertheless, if we accept them for the sake of argument, it is obvious that these new fossils have actually created a time interval of about 40 million years where fossils of snakes are entirely missing. Not surprisingly, this has not escaped notice. In a University of Alberta press release, Professor Caldwell says, “Importantly, there is now a significant knowledge gap to be bridged by future research, as no fossils [sic] snakes are known from between 140 to 100 million years ago.”8
The fact that, from an evolutionary perspective, mature, biologically diverse snakes already existed by 167 million years (the ‘age’ of the oldest fossil), leaves the evolutionary palaeontologists with no option but to argue for a much earlier origin for snakes. Confounding things further, evolutionists now find themselves facing another serious problem; the new snake fossils do not provide a shred of hard evidence for a pelvis or hind limbs.9
Snake evolution evolves
One of Caldwell’s colleagues, Sebastián Apesteguía (from the National Scientific and Technical Research Council, Argentina), now thinks snakes made their first appearance some 190 million years ago.2 Caldwell’s team advances what some see as a ‘novel idea’, that the snakes evolved their characteristic skull morphology long before losing their legs.10 In truth, they had little choice but to advance this ‘revolutionary’ view for two reasons: firstly, as stated earlier, skulls of all four of these ‘oldest’ snakes look like those of modern species; secondly, much ‘younger’ snakes (such as the 94 million year old Eupodophis) had small hind limbs. Consequently, in evolutionary terms, if they allow the fossils alone to guide them (but see below), the earliest snakes appear already limbless, only for limbs to reappear some 70 million years later—then, of course, to be lost again during many more millions of years. This kind of reversal is considered a no-no in evolutionary terms (a violation of Dollo’s Law11), as discussed here.
In reality, it is the scientists’ unwillingness to consider a non-evolutionary explanation for snake origins which has forced them to “rewrite the history of snake evolution”2 such is the power of the paradigm that this complete about-face doesn’t shake the confidence of the faithful! That evolution happened, somehow, is never in question.
How, then, do the researchers deal with the approximately 40-million-year gap? They must accept that the ‘sudden appearance’ of snakes, 100 million years ago, is actually a re-appearance. So, rather than it representing a sudden adaptive radiation of snakes as was thought until now (much as has often been argued for the Cambrian Explosion), they acknowledge that it’s actually a genuine gap in the serpent fossil record. For at least 67 million years prior to this time, they suggest, snakes must have been diversifying geographically and biologically—principally by virtue of elongation of the body and reduction in size of the legs—the latter in spite of there being no documented fossil evidence for limbs (or even limb girdles) for the first 70 million years of the snake fossil record!
Based on this paper, there will undoubtedly be a search for ever ‘older’ snake fossils (>167 million years) which, evolutionary scientists dearly hope, will cast some light on how an ancestral, non-snake reptile morphed into snakes. However, as far as we can tell from the fossils we have, snakes have always been snakes—which comes as no surprise to those who accept the Creator’s account of life’s origins. The snake fossil record still says no to evolution!
*While no legs are pictured by artist’s renditions of the other three fossil snake species, there is the possible suggestion of fore-feet in Portugalophis lignites; sheer artistic licence (footnote added 6 March).
References and notes
- Caldwell, M. W. et al., The oldest known snakes from the Middle Jurassic-Lower Cretaceous provide insights on snake evolution, Nature Communications 6, no. 5996, doi:10.1038/ncomms6996, 27 January 2015. Return to text.
- Dunham, W., Remarkable fossils push back snake origins by 65 million years, uk.reuters.com, 27 January 2015; accessed 5 February 2015. Return to text.
- The photographs and illustrations appearing in the paper’s figures are restricted to details of skull and jaw elements (plus teeth), and comparisons of vertebral bones. One can be sure that any pelvic or limb elements would have taken pride of place, had they been found. Return to text.
- In an earlier article, I made a related comment about other species of ancient snakes: “The fossil snakes with hind limbs mentioned earlier [Pachyrhachis problematicus and Haasiophis terrasanctus] actually pose a real dilemma for evolutionists: their skull structure is like that of allegedly ‘advanced’ snakes—such as boas and pythons—whereas the hind limbs are regarded as ‘primitive’!”; see creation.com/snakes. Return to text.
- The shared opening for the expulsion of fecal matter and urine, also used during copulation. Return to text.
- For example, see, Gillingham, J.C. & Chambers, J.A., Courtship and pelvic spur use in the Burmese python, Python molurus bivittatus, Copeia 1982(1):193–196, 1982. Return to text.
- Carpenter, C.C., Murphy, J.B. & Mitchell. L.A., Combat bouts with spur use in the Madagascan boa (Sanzinia madagascariensis), Herpetologica 34(2):207–212, 1978. Return to text.
- University of Alberta, The world’s oldest known snake fossils: rolling back the clock by nearly 70 million years, sciencedaily.com, 27 January, 2015; accessed 5 February 2015. Return to text.
- The best they can offer is “one potential sacral vertebra in Parviraptor estesi” (in contrast to most other snakes) and “another in the vertebral specimens referred to Diablophis gilmorei … ” That these are robust leads them to speculate about “the possible presence of robust pelvic girdles and hind limbs.” Return to text.
- This is the opposite of the conclusion of a recent paper on the fossil snake Coniophis precedens; Longrich, N. R., Bhullar, B. –A. S. & Gauthier, J. A., A transitional snake from the Late Cretaceous period of North America, Nature 488:205–208, 2012. Return to text.
- Dollo’s Law is named after Belgian biologist Louis Dollo. See: Dollo’s Principle: Irreversability [sic] of evolution, in Milner, R. (Ed.), The encyclopedia of evolution, Facts on File, Oxford, p. 143, 1990. Return to text.