Snakes evolved from four-legged lizards.  They lost their legs when they began to slither.  A very large number of intermediary forms in the fossil record provide evidence for this.  Coniasaurus was a snake-like reptile that had an elongated neck, torso, and tail, but also had four short limbs.[1]  Several fossils yield a range of dates from the early Cenomanian to the mid Santonian,[2] which is from 99.6 to 84.5 million years ago.  Haasiophis was an advanced snake that had small yet distinct hind legs.  It is from the early Cenomanian, corresponding to about 99 to 95 million years ago.[3]  Pachyrhachis was an advanced snake from the Cenomanian that had well-developed hind legs, but no front legs.[4]  Podophis was another advanced snake with legs from the same time.[5]          

     There are also a number of snake-like forms with limbs that lived in aquatic environments.  The sea monster lizards, the mosasaurs, are considered to be a relative of snakes, on account of shared characters such as thecodont tooth attachment,[6] elongated body form, skull similarities, reduced limb size, a second row of teeth on the upper palate, and kinetic jaws (meaning the jaw can crack open like a break-action shotgun to enlarge the mouth).  Another marine squamate, Adriosaurus, lived 95 million years ago.  It was similar to a snake in that it had a long and narrow trunk and tail, yet it had very small front legs and good-sized hind legs.[7]  Dolichosaurus was a four-legged marine reptile with small front legs, a break action kinetic jaw, and a very long snake-like neck and tail.  Its legs were apparently so small that they were useless, and were purely vestigial.[8]

     These half-snake half-lizard intermediaries congregate in the vicinity of 99 to 85 million years ago.  Therefore, one might assume that full-fledged snakes evolved sometime thereafter, perhaps 80 to 70 million years ago.  But this assumption is inaccurate. 

     Sound science, both from the fossil record and from molecular DNA, indicates that full-fledged snakes evolved before these intermediaries existed.  According to molecular evidence, snakes arose approximately 125 million years ago.[9]  According to the fossil record, the earliest indisputable snakes occur in the latter half of the Albian, which is about 106-99 million years ago.[10]  Thus, snakes were already up and running, or down and slithering, as it were, before these intermediaries with legs arrived in the Cenomanian.   

     Hence, despite the fact that the snakes with legs appear to be good intermediaries, they could not have been the true ancestors of modern snakes.  Instead, they were the descendents of a common ancestor they shared with snakes, i.e. – they were snakes' sister taxa. 

     The Cenomanian, some 99-93 million years ago, is the era when snakes first became common.  Far from being primitive, they were already well-advanced, even though they were very early.  From the beginning, snakes were macrostomatan, that is, they possessed a unique skull and muscular structure in the head that allowed them to swallow prey bigger than their own diameter.  In this character, they appear to have skipped over the scolecophidea and alethinophidea branches of the order serpentes, which, according to molecular DNA analysis, should have come before them as evolutionary steps toward the more advanced macrostomatan form.[11]  It is strange that snakes would reach such an advanced form so early, as Rage and Escuillies said,

 

The three hind-limbed snakes have a macrostomate skull; but in existing snakes this character appears only in forms considered to be the most "advanced," the macrostomata, a priori, this structure should be derived… the presence of hind legs and macrostomate structure, poses a serious problem.[12]

 

Reippel et al commented in like manner,

 

With Haasiophis, Pachyrhachis, and Podophis representing macrostomatan snakes, the question of the sister-group relationships of snakes within Squamata, or of snake "origins," remains unresolved.  Nevertheless, the presence of snakes with macrostomatan characters at 95 Ma (million years ago) indicates that a series of cladogenetic events leading to the major extant groups of snakes occurred prior to the mid-Cretaceous.[13] 

 

     This means that snakes had already diverged and become advanced prior to 99 million years ago.  Therefore, a significant amount of snake evolution must have occurred that has not been preserved in the fossil record.  Either this evolution occurred tens of millions of years beforehand in the early Cretaceous, as Darwinists would prefer; or, it occurred so quickly that the fossils were not preserved.  The latter accords better with the actual fossil data, because the fossils don't go back beyond the Albian.

     The problematic nature of snake origins has also led to a debate on aquatic versus terrestrial origins.  Caldwell suggested that "snakes, mosasauroids, dolichosaurs, and coniasaurs may have a common aquatic ancestor."[14]  But Wiens et al maintained that snakes evolved from terrestrial burrowing reptiles,[15] because the two most basal lineages of snakes are burrowers – the scolecophidians and the annelids.[16]

     It is a problematic pattern often observed in the fossil record.  When we reach back in time to the beginnings of a new life form, we often find a woefully incomplete or non-existent record for how that life form came about.  There are three possible explanations for this:  

1) Either the fossil record is poorly preserved, or

2) Some intelligent being suddenly creates new forms out of thin air, or

3) New forms evolve so quickly that there is not enough time for the missing links to leave fossils. 

     Applied to snakes, the problem with the first hypothesis is that the fossil record is not poorly preserved.  As demonstrated above, the fossil record adequately recorded a host of intermediary forms.  It has also provided us with innumerable specimens of lizards, mosasaurs, full-fledged snakes, etc.  Surely, if snakes evolved gradually over millions of years, we should expect to find intermediaries that predate the appearance of advanced snakes 95 million years ago. 

     The problem with the second hypothesis is that intermediary forms do exist.  If God created snakes out of thin air, then why do we see so many snake-like forms with reduced limbs in the fossil record?  Moreover, traces of the rear legs are found in some snakes even to this day.  Why would a Creator God make snakes with legs they don't need?

     Only the third hypothesis makes sense.  If snakes evolved rapidly, then the missing links did not exist long enough to leave fossils.   Nevertheless, the missing links did have children, some of which still retained sizeable legs.  It is these descendents of missing links that are found so frequently in the fossil record.  Although the intermediaries with reduced limbs occur too late to be the missing links themselves, they are the right age to be the descendents of the missing links.  Thus, when snakes evolved from lizards, their transformation happened so quickly that the missing links were not preserved, yet the children of those missing links show up millions of years after the transformation, as contemporaries of the more advanced forms.

     The loss of all traces of legs in snakes is known to occur very slowly over time.  For example the annielline and anguine snakes are known from 50 million years ago, yet still retain the pectoral girdle bones.[17]  Even after 100 million years, natural selection has failed to complete the transition, for some snakes today still possess vestigial elements of hind limbs.  The traces of vestigial legs in snakes even after 100 million years, is a testimony to how slow and inefficient natural selection actually is. 

     It appears as though there are two types of evolution.  One type generated a massive transformation from lizards to snakes in just a short time.  The other type has been gradually trying to tidy up the last vestigial remnants of that transformation – a process it still has not completed even after 100 million years.  One type of evolution is rapid.  The other type is gradual.  Gradual evolution has accomplished less in 100 million years than rapid evolution accomplished in a much shorter period of time. 

     The best explanation for this is that there are two separate mechanisms that bring about evolution – the gradual mechanism being natural selection, as Darwin described it, and the rapid mechanism being some other kind of force.