the year in books [XII]

This gauntlet covers a slew of American westerns. Mary Russell's Doc (5⭐️)was the best of them all, an excellent retelling of the story of Doc Holliday's life. She doesn't go into much detail about the shoot-out in Tombstone and its fallout, probably because she addresses that in another novel, Epitaph (which is in my queue). Robert Bausch's As Far As The Eye Can See was a quick and delightful read, so it, too, gets 5⭐️. Terry C. Johnston's Crack in the Sky, book three of his nine-book Titus Bass series, chronicles Bass' further adventures in the Rocky Mountains, and it's won 5⭐️. Elmer Kelton's Many A River was, like Bausch's novel, a quick and delightful read (5⭐️), so I was surprised when I didn't find his The Rebels: Sons of Texas to be engaging (3⭐️). Loren D. Estleman's Port Hazard (4⭐️), another entry in his ongoing Page Murdock serial, found the deputy sheriff out in San Francisco. Though it's one of the least-liked of his Murdock series, I found it interesting in how he accurately captures the atmosphere of San Francisco's early days. 

the year in books [XI]

Every year I try to read a few books on the world wars, and these are some of this year's collection. Max Hasting's 1914: Europe Goes to War chronicles the events that led to the Great War (a.k.a. World War One) and how that war began up until the evolution of trench warfare on the western front. William Craig's Enemy at the Gates details the Germans vs. Russians at the Battle of Stalingrad; he pays particular attention to the experiences of soldiers and civilians, making this a phenomenal book. I wasn't as impressed with Prit Buttar's Retribution, which picks up after Stalingrad, for he deals mostly with logistics and tactics rather than fleshing out what it was like for the boots on the ground. Walter Lord's Day of Infamy: The Bombing of Pearl Harbor was a decent book. It's filled mostly with anecdotes of peoples' experiences, but there's little cogency. One minute you're on the deck of the U.S.S. Arizona, then you're at Hickam Field, and then you're in the pilot seat of a Japanese dive bomber. It gets confusing. Adam Makos' A Higher Call and Spearhead were both excellent books, the first dealing mainly with the air war over Germany from the German point-of-view, and the latter following an American tank company in Germany. 

family devotions: "On Abortion"

Abortion has been a hot topic for decades. There are those who are 'pro-choice,' believing that it is a woman's right to determine whether or not she carries a baby to full term. There are those who are 'pro-life,' who believe that the purposeful extinction of a baby in the womb is tantamount to murder. Debaters on either side often get swept up in the definition of terms, wrangling over what constitutes a baby: is the organism developing in the womb merely a clump of cells until birth, or should it be given the full value of personhood at conception? Science can answer a lot of these questions, but science is silent when it comes to morality. As Christians, our definition of right and wrong needs to come from what God says. In other words, does the Bible tell us anything about the morality of abortion? Are the unborn full human beings or just clumps of cells? If fetuses are full human beings, then abortion is indeed tantamount to murder. If they are just clumps of cells, then perhaps abortion isn't that bad, after all. Ultimately the question is how does God, the Creator, look at it? While the Bible doesn't explicitly give us an answer, it does address the subject in roundabout ways. Examination of several passages indicates that abortion should indeed be viewed as murder; to interpret the passages otherwise requires a great amount of 'logic-stretching' informed not by the text but by cultural biases. 

Isaiah 44.24 reads, 'Thus says Yahweh, your Redeemer, who formed you from the womb: 'I am the Lord, who made all things, who alone stretched out the heavens, who spread out the earth by myself." In this text from Isaiah we see that the Creator of the Cosmos extends His creative power to the womb; He is intimately involved in forming people not 'out of the womb' but 'from the womb.' It seems that personal identity - person-hood - is evident in the womb. Psalm 139.13-16 reads, 'For you [God] formed my inward parts; you knitted me together in my mother's womb. I praise you, for I am fearfully and wonderfully made. Wonderful are your works; my soul knows it very well. My frame was not hidden from you, when I was being made in secret, intricately woven in the depths of the earth. Your eyes saw my unformed substance; in your book were written, every one of them, the days that were formed for me, when as yet there was none of them.' Here we see two key things: first, there is a reaffirmation that God is involved in the 'creation process' of the womb; and second, person-hood in the womb is reaffirmed (the psalmist's identity is intact while being 'knitted' in the womb). Another text is Luke 1.41-44, which recounts the tale of the pregnant Mary visiting her pregnant cousin Elizabeth, who was carrying John the Baptist. Verse 41 tells us that "when Elizabeth heard Mary's greeting, the baby [John the Baptist] leaped in her womb, and Elizabeth was filled with the Holy Spirit." Even in utero, John the Baptist was cognizant of Jesus' approach. Verse 44 tells us that "the baby in [Elizabeth's] womb leaped for joy." This is not the action of clumped cells! In Amos 1.13-15 the prophet condemns the sins of the Ammonites: "This is what Yahweh says: 'For three sins of Ammon, even for four, I will not relent. Because he ripped open the pregnant women of Gilead in order to extend his borders, I will set fire to the walls of Rabbah that will consume her fortresses amid war cries on the day of battle, amid violent winds on a stormy day. Her king will go into exile, he and his officials together,' says Yahweh." The Ammonites had committed a particularly heinous war crime in that they ripped open the bellies of pregnant women; some have argued that the atrocity wasn't so much what they did but either (a) the motivation behind it - enlarging their borders - or (b) the fact that it wasn't their choice to do so (it is a choice the pregnant women of Gilead were to make themselves!). This is nonsensical poppycock. The fact of the matter is that God looked upon their actions as utterly reprehensible and condemned them for it.

The passages above indicate that even in the womb, the value and experience of person-hood is intact. They indicate that the 'snuffing out' of unborn children is a heinous sin. Exodus 21.22-25 gives us a more poignant snapshot of God's feelings on the subject. The text reads: "When men strive together and hit a pregnant woman, so that her children come out, but there is no harm, the one who hit her shall surely be fined, as the woman's husband shall impose on him, and he shall pay as the judges determine. But if there is harm, then you shall pay life for life, eye for eye, tooth for tooth, hand for hand, foot for foot, burn for burn, wound for wound, stripe for stripe." Here we see that the punishment for causing an unintentional abortion is 'life for life'; thus God views life in the womb as fully fledged human life, and to take it isn't just 'killing' a human but murdering one - and justice demands that murderers be killed (note, of course, that this doesn't mean Christians should start bombing abortion clinics!). 

We must ask ourselves, "Why do people want abortions?" In the vast majority of cases, those who get abortions do so because children don't fit their personal desires or ambitions. Psalm 127.3 tells us that children are a blessing from God, but our culture hates God and His blessings. At the best, our culture is resistant to the biblical reality that children are a blessing - and this thinking has even infected the American church. Until recently, it was assumed by Christians that God wants His people to get married and have kids; it's part of the way that God's kingdom grows. Nowadays even Christians will postpone having children or will refuse to have children for personal or even political reasons. The clear testimony of scripture, however, is that mankind was created to procreate; that one of the foundational purposes of marriage is procreation; and that God desires His people to grow their families. These principles have been set aside for personal aims and ambitions. Our godless culture hates children and many Christians have been adopting that posture but with religious lace. Thankfully there are strong movements against such thinking in the church.

Many people will ask, "Well, is abortion okay in the context of rape?" What if you're raped and conceive? Is God okay with an abortion in that instance? Never mind that such an occurrence is extremely rare, because it has happened. Deuteronomy 24.16 tells us that 'fathers shall not be put to death because of their children, nor shall children be put to death because of their fathers. Each one shall be put to death for his own sin.' Extrapolating from this principle, I would argue that abortion would not be justified in this case. Why should the child, though conceived in sin, be punished because of the actions of his or her father? To abort the conceived child would be to pile one injustice upon another. This is a tough pill to swallow, for it's certainly not fair to the mother. No one is saying that it is. But often in life, godly duty isn't easy and isn't what we would choose for ourselves.

What if you find out your in utero child has genetic defects? This is the worst nightmare of any soon-to-be parent, for good reason. We want what is best for our children; we want them to flourish; and genetic defects of all stripes can affect our child's propensity for such a life. In this case, is abortion justified? Exodus 4.11 tells us, "Who has made man's mouth? Who makes him mute, or deaf, or seeing, or blind? Is it not I, Yahweh?" Remember that God is intimately involved in the in utero creation process; according to this text, genetic defects are even in His power. Defects are just that: defects. They come about due to the Fall and the death and decay that infects humanity. Whether or not God causes defects in the womb is beside the point, since at the very least He allows them for His own purposes. This means that those with defects are not worth less than those operating with a full deck. In utero babies with genetic defects aren't to be discarded but loved and cherished. Though many in our culture will opt for abortion when they learn that their child has genetic defects, the fact is that the majority of those who refuse to abort end up being grateful that they didn't. 

The biblical testimony is that abortion - the murdering of an unborn child - is a heinous sin that needs to be resisted by Christians. It's sad that many Christians don't see a problem with it. They've been seduced by cultural thinking that forces them to turn a blind eye to what the Bible actually says. Our culture celebrates the murder of unborn children and values it as an expression of women's rights. It's assumed that a woman has the right to choose what is best for her body, even if that entails the murder of her own child. Those who have had abortions have, to put it bluntly, murdered their own children. The good news is that because of Jesus' sacrifice and God's grace, those who have murdered their children can confess their sin, turn from their evil ways, and be healed and accepted as full-fledged children of God. 

The Rauisuchians

The Middle Triassic Ticinosuchus goes for a stroll

The rauisuchians were a group of Triassic archosaurs that usually grew between three and thirty feet in length and stood between two and a half and nine feet tall. Nowadays the group “Rauisuchia” is considered an evolutionary grade or ‘wastebin taxon’ in that it includes most of the large, predatory carnivorous pseudosuchians that lived during the Triassic Period and which didn’t fall into the crocodylomorpha. Modern studies indicate that the rauisuchians weren’t a natural group but is a ‘catch-all’ that includes a number of smaller clades, such as the proper Rauisuchidae, the Ctenosauriscidae, and the Shuvosauridae. Thus the ‘rauisuchians’ become a group of pseudosuchian archosaurs that are more closely related to one another than they are to other pseudosuchians. Many rauisuchians are well-known, such as the Middle Triassic Ticinosuchus of Europe, the Late Triassic Saurosuchus of Argentina, and the Late Triassic Postosuchus of North America. 

a pair of Postosuchus attack the aetosaur Desmatosuchus

The rauisuchians didn’t blow up to epic proportions until the Late Triassic. At their genesis earlier in the Triassic, they were relatively small and would’ve fed on small lizards and proto-mammals. As they grew larger as the millions of years eked by, they became better suited for taking down large prey, such as the tusked dicynodont therapsids that flourished during the Triassic. Towards the Middle and Late Triassic they became the top predators, the terror of Triassic nightmares. Rauisuchians, along with all their pseudosuchian brethren except for the crocodylomorphs, were wiped out during the Triassic-Jurassic extinction. Their disappearance meant that their niches as top predators could be filled by entrepreneurial critters, and theropod dinosaurs moved into the vacuum: it’s likely that their ability to grow larger is linked, at the very least, with the disappearance of the rauisuchians, which had preyed on the smaller theropod dinosaurs in the twilight of the Late Triassic. Some paleontologists speculate that a lineage or two of rauisuchians survived into the Early Jurassic before being outdone by the opportunistic theropods, but this is mere speculation based on questionable bone fragments from South Africa. 

a panoply of larger-sized rauisuchians

the tyrant rauisuchian Fasolasuchus attacks a prosauropod 

Rauisuchians in the Middle and late Triassic grew to enormous sizes, and scientists have speculated that the largest of them all – Fasolasuchus – evolved to specifically prey on the larger Late Triassic prosauropods such as Plateosaurus and Riojasaurus. The carnivorous rauisuchians generally had thin, sharp, serrated teeth used to tear chunks out of their prey. The prey, wound down and missing good amounts of flesh, would’ve collapsed due to shock or blood loss to find a new home in a rauisuchian stomach. Rauisuchians could rear up on their hind legs for short amounts of time; by doing this they could scout for prey or enemies, and when hunting they could raise up and come crashing back down to intensify the lethality of their blows. Some rauisuchians were capable of a semi-bipedal lifestyle; rather than being able to simply rise up and down on their back legs, they could actually run on them. Examples of semi-bipedal rauisuchians include Postosuchus and Sillosuchus. Rauisuchian legs were positioned vertically beneath the body rather than sprawling outward. Though this type of gait is seen in dinosaurs, it evolved independently between the two groups. Rauisuchians had a hip socket that faced downward to form a shelf of bone under which the femur connects (a ‘pillar-erect’ posture), whereas dinosaurs have a hip socket that faces outward with the femur connecting to the side of the hip (an ‘erect’ posture). When covered in flesh, both hip arrangements give the same appearance; it’s only when muscle and tendon are removed that the differences become evident. 

Arizonasaurus of Middle Triassic Arizona

Two clades of “rauisuchians” – the Ctenosauridae and Shuvosaurids – deserve honorable mention, since they vary so greatly from the general rauisuchian morphology. The ctenosaurs had long spines on their backbones that probably supported a big sheet of skin. Other prehistoric creatures had such ‘sails’: the mammal-like Dimetrodon of the Permian, for example, and the sail-backed dinosaur Spinosaurus. The evolution of sails in these creatures and the ctenosaurs is an example of convergent evolution, wherein different species unrelated to each other evolve similar traits independently. Scientists speculate about the purpose of these sails; though it was once thought that they helped with thermoregulation, this theory has become outdated due to the fact that all the creatures mentioned above were already self-regulating their body temperatures (i.e. they were warm-blooded). The sail’s function was most likely for species recognition or sexual displays; the male with the biggest and most colorful sail, for instance, may have captured the most prized females. Ctenosaur fossils have been found throughout the world in North America, Europe, Africa, and China. The North American Arizonasaurus (discovered, I’m sure you guessed, in Arizona) lived during the Middle Triassic and was found as a complete skeleton, sail included. It had long jaws full of sharp teeth. However, not all ctenosaurs were necessarily carnivores: the Chinese Lotosaurus is an unusual ctenosaur because it had a short head and toothless beak, indicating that it may have been a plant-eating variant (though turtles also have beaks and are omnivorous). 

the pseudosuchian Effigia; despite an obvious resemblance
to later theropod dinosaurs, this creature was more closely
related to crocodiles than to birds

The shuvosaurs include Shuvosaurus and Effigia from the American Southwest and Sillosuchus from Argentina. These pseudosuchians had long back legs and short front legs, indicating they were bipedal. Their necks were long, and in place of jaws of sharp teeth they had ostrich-like beaks. Their resemblance to the ostrich-like theropods during the Jurassic and Cretaceous Periods are instances of convergent evolution, and for a while they puzzled paleontologists who thought they may have been earlier dinosaurs of the same type. The shuvosaurs may be related to the herbivorous ctenosaur Lotosaurus, carrying on its beak but losing its sail. The Triassic shuvosaurs are considered plant-eaters. 

The Ornithosuchids

The Ornithosuchids are a small archosaurian group with only four known genera: Ornithosuchus (the namesake), Riojasuchus, Venaticosuchus, and Dynamosuchus. The Ornithosuchids were quadrupedal but able to move about on their hind legs for short periods of time (perhaps when requiring an extra burst of speed when chasing prey). They were widespread during the Carnian and Norian stages of the Late Triassic. Their skulls resembled those of theropod dinosaurs and - unsurprisingly - they were carnivorous. 

Riojasuchus likely grew to about six feet snout-to-tail

Though they looked similar to other archosaurs – especially the phytosaurs and rauisuchians – they had several distinctive traits. They had a small fenestrae between the palatine and pterygoid bones of their upper mouth; the contact between the nasal and prefrontal bones of the skull is small or absent; they have distinctive downturned snouts; and – most importantly – their ankles are in what’s called a ‘crocodile-reversed’ formation. Archosaur groups in general can be distinguished from one another based on the structure of their ankles. Most archosaurs had a ‘crocodile-normal’ ankle, but Ornithosuchids are unique in that they have a ‘crocodile-reversed’ ankle. 

Ornithosuchus – the group’s namesake – grew to about thirteen feet in length and lived during the Carnian stage of the Late Triassic. Its name means ‘bird crocodile,’ and it had a double row of armored plates along its back. It was originally thought to be the ancestor of the carnosaurian dinosaurs (such as Allosaurus and kin), but it’s now recognized as being more closely related to crocodilians than birds. 

Ornithosuchus feasting on a tusked dicynodont

The Erythrosuchids

a pair of Early Triassic Erythrosuchus

The erythrosuchids are popularly known as the ‘Crimson Crocs’ (their name literally means ‘red crocodiles’), and these tank-like pseudo-crocs lived from the later stages of the Early Triassic to the early Middle Triassic. These croc-like predators were the Top Dogs in the Early and Middle Triassic. They had large, deep heads and powerful jaws. Erythrosuchus, the group's namesake, appeared in the Early Triassic and thrived till the Middle Triassic; it grew up to sixteen feet long; in the Late Triassic, after its extinction, the ecological niche of 'Top Predator' was overtaken by archosaurs like Saurosuchus and Postosuchus.

Shansisuchus, a Middle Triassic erythrosuchid

The erythrosuchids grew between eight and fifteen feet in length. Though they look like archosaurs, they’re technically archosauriformes, having evolved prior to, if not in tandem with, true archosaurs. While they share many characteristics with archosaurs, morphological differences demand that they be placed in a cousin-like relationship with the reptiles that dominated the Triassic Period. Unlike archosaurs, erythrosuchids lacked teeth on the palate, and the lower margin of the bone at the tip of the upper jaw (the premaxilla) is lower than the margin of the maxilla, the bone behind the premaxilla; this arrangement created a particular ‘step’ that makes erythrosuchids easily distinguishable from other archosauriformes (which have smooth jaw margins that are either straight or gradually curved). The erythrosuchids are notable for being the first archosauriformes to develop a triradiate pelvic girdle with three projecting areas from the ilium, pubis, and ischium. The fourth tronchater – a ridge on the femur that attached muscles in archosaurs – appears first in erythrosuchids, hinting at a close relationship with the archosaurs. 

an Erythrosuchus in a Middle Triassic dried-up riverbed

The Aetosaurs

a Desmatosuchus searching for food in a fire-scorched wasteland

The aetosaurs – ‘eagle lizards’ – were heavily-armored, medium- to large-sized Late Triassic herbivorous reptiles. They were easily distinguishable, having small heads, upturned snouts, erect limbs positioned beneath their bodies, and most notably they were covered by plate-like bony scutes. Over twenty different kinds of aetosaurs have been discovered, and their remains come from every continent but Australia and Antarctica, giving them a nearly worldwide distribution during the Late Triassic. 

Aetosaurus

All aetosaurs belong to the family Stagonolepididae, but all fall within two distinct subdivisions: the Aetosaurinae and the Desmatosuchinae. The differences between these two groups focus on the arrangement of their armor. The Aetosaurines have projections called eminences on their dorsal paramedian osteoderms close to the midline of their backs. The Desmatosuchines have grooves on their dorsal paramedians that locked the lateral plates in a tight articulation, and many desmatosuchines had long spikes that projected from their lateral plates. These spikes are especially pronounced in Desmatosuchus, the group’s namesake. Some aetosaurines had spikes, but they had less and these weren’t as prominent. Some aetosaurines, such as Aetosaurus, had smooth carapaces that lacked spikes. Phylogenetic studies indicate that the aetosaurs may have been closely related to crocodylomorphs. Aetosaur evolution is pretty murky, as they show up on the scene in the Late Triassic fully-formed and with no ‘transitional species’ from ancestral archosaurs. Scientists postulate that the aetosaurs emerged in the Early or Middle Triassic before diversifying and flourishing in the Late Triassic. Primitive genera, such as the successful Aetosaurus in the Norian stage and Coahomasuchus in the Carnian stage, tended to be small, reaching three feet in length; later advanced forms could reach up to ten feet in length. Some aetosaurs, such as Typothorax, had broad, turtle-like bodies and reached eight feet in length; the spiked and narrow-bodied Desmatosuchus reached at least thirteen feet in length. 

an Aetosaurus roots around in the soil, looking for food

Aetosaurs lived on land and ate the ferns and seed ferns that flourished in the Triassic. Aetosaur teeth were simple and conical, designed for vegetation rather than meat. The tips of their upturned jaws were toothless and probably supported a keratinous beak. Because aetosaurs teeth show little wear and tear, it’s assumed that they didn’t eat tough and fibrous plant material but the softer leaves of ferns. They may have dug up roots and tubers with their upturned snouts, and there’s further evidence that they were diggers: their muscles were designed for digging motions, and their oversized hind feet sported large claws that could’ve been used for scratch-digging. Though some studies have indicated aetosaurs may have been burrowers – at least in the case of the smaller, more primitive forms – aetosaurs lack several characteristics seen in other burrowers. A 2009 study of the aetosaur genus Neoaetosauroides suggests that these animals may have fed on bug larvae and insects that lacked hard exoskeletons; this genus of aetosaur had a jaw leverage that wouldn’t be suitable for strong forces such as crushing and chopping needed for an herbivorous diet. Thus some aetosaurs, though certainly not all, may have been insectivores. 

several aetosaurs find themselves wedged between a forest
fire and some hungry phytosaurs

Aetosaur heads were flat and blunt at the front, resembling a pig’s snout. They had a ‘pillar-erect’ posture with their legs positioned underneath their bodies. Their feet resembled those of the crocodile-like semiaquatic phytosaurs. Though aetosaurs hind-limbs were much larger than the forelimbs, they remained nevertheless quadrupeds. Even if they’d wanted to go about on two legs, such a feat would’ve been exhausting because of their heavy armor. This armor, undoubtedly designed as a defense against predators, consisted of large quadrangular interlocking bony plates (called osteoderms) that protected the back and sides, belly, and tail. Most osteoderms were heavily pitted on their upper surfaces and smooth on their undersides. The center of the osteoderms was made up of spongy bone, and the outer parts were formed by compact bone. These plates were probably covered in horn. Dorsal osteoderms – found on the back of the animal – were often ornamented with radial grooves. Dorsal paramedians – found along the animal’s midline – were usually wide and quadrangular with a small boss called a dorsal eminence on the surface of each plate. The paramedian plates on aetosaurs often had raised or depressed edges where the plates articulated with the ones in front of them, giving them an almost ‘scaly’ appearance. In the lateral plates – positioned on either side of the paramedian plates – the dorsal eminence was often enlarged into a pronounced spike. These spikes are vividly evident in Desmatosuchus and Longosuchus. 

plate armor didn't mean aetosaurs were invincible: here a Postosuchus defends its kill
against a rival

The Crocodylomorphs

the Late Cretaceous Deinosuchus attacking a tyrannosaur

The crocodylomorphs are a group of archosaurs that continues today with modern crocodiles. Because our interest here is in the crocodylomorphs of the Mesozoic – often called ‘proto-crocs’ to distinguish them from modern species – we won’t examine their evolutionary path far beyond the Cretaceous-Tertiary Extinction Event. The Mesozoic was the heyday of crocodilian ancestors, as they reached greater diversity and abundance than they currently enjoy. It was during the Age of the Dinosaurs that they reached titanic sizes that make modern crocodiles look like puny wimps just begging to be beat up on the crocodilian playground: Sarchosuchus reached thirty feet in length and Deinosuchus forty feet, dwarfing their modern counterparts who clock in around fourteen feet (the Nile crocodile), seventeen feet (the saltwater crocodile), and sixteen feet (the American alligator). This isn’t to say all Mesozoic crocodylomorphs reached epic proportions, for Knoetschkesuchus grew only to fifty-five centimeters in length!

not all crocodylomorphs reached epic sizes

Modern crocodilians include only twenty species, and most of them look similar and lead similar lifestyles; this prompts one to imagine that the crocodilians of the past were similarly like-minded, but this would be a mistake. As one paleontologist puts it, “There are no long-legged running crocodiles or deep-diving ocean crocs [today]; no crocs the size of Chihuahuas and none the sizes of T. rex, either; and no living croc has blade-like teeth or eat plants. But that was not always the case.” He continues, “Living crocs are not big, slow-moving, semi-aquatic animals because they are primitive. Those characteristics are evolutionary adaptations for their current way of life.” As we will see, the crocodilians of the Mesozoic were a diverse and interesting lot that, in many ways, put their modern descendants to shame! As we explore the crocodilian lineages of the past, the cladogram below can help make sense of the various cul-de-sacs and detours the Mesozoic crocs took in their development:

Hesperosuchus

The first crocodylomorphs appear in the Late Triassic, and they looked nothing like crocodiles as we know them today. They were small, lightly-built, agile, and quick-footed creatures whose limbs were built directly beneath their bodies (they didn’t ‘sprawl’ like modern crocs). Paleontologists have often described them as ‘reptilian wolves’ built like greyhounds. One scientist put it this way: “Imagine a greyhound dog with scales and a long tail, and you’ll have a pretty good picture of most sphenosuchians.” These early proto-crocs probably ate insects and other small animals, and they survived into the Middle Jurassic before being supplanted by their larger evolutionary descendants. The earliest species was Hesperosuchus in the Late Triassic, and the last known sphenosuchians was Junggarsuchus in the Middle Jurassic. Hesperosuchus grew four to five feet in length, was lightly built and agile, and it had strong hind-limbs with smaller, slender front limbs. Some hypothesize that it may have been bipedal (or at least able to move about on two legs, perhaps when chasing prey). It’s been discovered in Arizona and New Mexico, and during the Late Triassic that area was cut by streams and peppered with lakes and ponds. Though Hesperosuchus was fully terrestrial, it prowled these waterways hunting supersized amphibians, perhaps snagging fish, competing with the burgeoning fast-running theropod dinosaurs and dodging the tyrannical phytosaurs of its day.

Redondavenator from New Mexico is another sphenosuchian that has acquired lots of attention. It was a large creature with a skull at least two feet long. It lived at the very end of the Triassic Period, when the rauisuchians – the predatory heavyweights of much of the Triassic Period – had gone extinct. Because the predatory theropod dinosaurs had yet to bloom in size to fill the ecological niche left vacant by the demise of the rauisuchians, Redondavenator may have filled that role before the evolution of large theropod dinosaurs such as Dilophosaurus.

The sphenosuchians didn’t last past the Middle Jurassic, but crocodylomorphs did. First to evolve were the ‘protosuchians’, or primitive crocodiles, which were the least like the crocodiles we know today. The protosuchians reached between three and nine feet in length, and they were adapted for life both on land and in the water. None of them got too big, and they survived through the Jurassic and into the Early Cretaceous Period. Next came the ‘mesosuchians’, or middle crocs, which had more in common with modern crocs but would still look out-of-place if we came across them today. The mesosuchians have been subdivided into four different groups, each with their particular characteristics: the ocean-dwelling thalattosuchians, the heavily-armored notosuchians who decided to go vegan, and the ‘eusuchians,’ or true crocs, which consist of all living crocodiles and their closest extinct relatives. 

You may have noticed, however, that only three groups were just mentioned; that’s because the fourth is an odd anomaly. Because it doesn’t pertain to the Mesozoic, a brief quip will suffice: Sebecus – named after the crocodile-headed god of ancient Egypt – lived during the Eocene epoch of the Tertiary Period, and it had theropod-like teeth. When its skull and teeth were discovered, it prompted a mad scramble: “Did some theropods survive the end of the Mesozoic?” False alarm, for these theropod teeth belonged to an odd breed of crocodile. Sebecus had a thin, blade-like teeth and a long, tall, narrow snout (much like a theropod dinosaur). Sebecus lived in South America during the early Cenozoic and competed with few large mammalian predators; instead if competed with large flightless birds with hooked beaks. Paleontologists don’t know if Sebecus evolved in the early Cenozoic to adapt to a new post-apocalyptic environment or if it was a survivor of a currently unknown lineage from the Cretaceous; if the latter, its skull and teeth would be examples of convergent evolution that made it appear similar – at least in respects to the skull – to heavyweight theropod dinosaurs. This wouldn’t be too surprising, as another crocodile lineage – that of the herbivorous notosuchians – ended up looking a lot like ankylosaurs and playing similar ecological roles. 

the Eocene crocodilian Sebecus; note the 'theropod' look of its skull

But let’s get back to the crocodilians of the Mesozoic. We begin with the ocean-going thalattosuchians that thrived in the Jurassic Period. These crocodilians lived full-time in the ocean, unlike modern saltwater crocs that will swim the ocean but remain ‘at home’ along shorelines. Thalattosuchians were long- and slender-bodied with paddle-like limbs; a few even had shark-like vertical fins at the end of their tails. Many had porous bones like modern animals – such as whales and seals – that dive deep into the ocean. Though fully aquatic, these crocodilians likely came onto land like sea turtles to lay their eggs. The ten-foot-long Metriorhynchus had a streamlined body, paddle-like forelimbs, and a finned tail like fishes; the fifteen-foot-long Dakosaurus had a strong skull and killer teeth designed to kill and eat large marine reptiles like ichthyosaurs or plesiosaurs. 

Dakosaurus, a Jurassic thalattosuchian

the boxy skull of the herbivorous Simosuchus

The notosuchians were small, heavily armored crocodilians that adopted an herbivorous lifestyle. They had short heads that resembled bulldogs, and their jaws were filled with multicusped, mammal-like teeth. They lived fully on land and ate plants. In a case of convergent evolution, these armored crocodilian tanks looked a lot like the armored ankylosaurs. It’s interesting that no ankylosaur fossils have been found in South America, Africa, or Madagascar – but notosuchians thrived there! It seems that the niche filled by ankylosaurs in the northern hemisphere was filled by notosuchians in the southern part of the planet. Like ankylosaurs, they went extinct at the end of the Cretaceous. Notable notosuchians include Uruguaysuchus from South America, Chimaerasuchus from China, Malawisuchus from Africa, and Simosuchus from Madagascar.

The fourth group of mesosuchians continues to this day. The eusuchians – or true crocodiles – first made their appearance in the Cretaceous Period and have survived until the present day in the twenty species of crocodiles we can visit in the wild or see at zoos. The current crocodiles don’t differ much from their Cretaceous ancestors, so to say that they look ‘primitive’ as relics from the Mesozoic Era isn’t far off the mark. Eusuchians, ancient and modern, are designed for a semi-aquatic lifestyle. The most notable difference between modern eusuchians and their Mesozoic counterparts is their size: the largest eusuchians from the Mesozoic had skulls between four and five feet in length and reached up to thirty-three to forty feet in length (Deinosuchus topped out around forty feet head-to-tail). 

an artist's rendition of Deinosuchus from the Cretaceous Period

The Phytosaurs

Phytosaurs were large, heavily-armored, (mostly) semi-aquatic predators of the Late Triassic. When their remains were first discovered, they were erroneously thought to belong to an herbivore, hence the name ‘phytosaur’ – which literally means ‘plant reptile.’ The fact that these creatures were feisty predators is, then, rather ironic. Generally speaking, phytosaurs were long-snouted, covered in armor, and upon a quick glance resembled modern crocodiles in plenty of aspects. This is an example of convergent evolution, in that phytosaurs were adamantly not crocodiles. Though they were distantly related to the crocodiles we know today, they weren’t ancestral. The crocodilian ancestors of the Triassic – the crocodylomorphs, or ‘proto-crocs’ – lived side-by-side with the phytosaurs but resembled reptilian wolves. It wasn’t until the Early Jurassic that proto-crocs became ‘crocodilian’; or, to put it in a more honest way, became ‘phytosaur-like’! It isn’t that phytosaurs resemble crocodiles; it’s that crocodiles resemble phytosaurs! Phytosaurs, after all, came first. 

a phytosaur takes center-stage among early crocodilians
and a Coelophysis

The phytosaurs first appear in the Carnian stage of the Late Triassic. They have no welcoming committee, no ‘transitional fossil’ heralding their arrival. They show up on the scene as full-fledged, highly-specialized semi-aquatic predators unlike most of their contemporary terrestrial archosaurs. They spread across Pangaea like kudzu, gaining a nearly global distribution during the Triassic. Only in southern Pangaea, where the environment was much drier, were they hard-pressed to thrive. The first phytosaurs were ‘basal’ in the sense that they weren’t highly-specialized for particular environments (despite being specialized for semi-aquatic living). In the late Carnian, more specialized forms emerged, such as Rutiodon, Leptosuchus, and Smilosuchus. These specialized phytosaurs died off in the Carnian-Norian extinction, and the surviving phytosaur lineages were more basal and thus more able to adapt to changing environments (the more specialized you become, the harder catastrophe hits). By the middle of the Norian stage of the Late Triassic, advanced and specialized phytosaurs were reemerging, such as the highly successful fish-eating Mystriosuchus. Phytosaurs underwent rapid diversification and specialization throughout the Norian and into the Rhaetian, but their star-studded rise to fame died out in the twinkling of a geologic eye at the Triassic-Jurassic Extinction Event. Crossing into the Jurassic Period, phytosaurs are nowhere to be found. Sure, some paleontologists have argued that a lineage or two survived into the early Jurassic, but evidence is lacking or at least misleading. For example, what looks like phytosaurs teeth have been found in early Jurassic rocks, but these could easily be misidentified; and the remains of a supposed phytosaur from the Early Jurassic turned out to be, upon closer examination half a century later, the remains of a sauropodomorph dinosaur. 

Phytosaurs grew between two to twelve meters in length and averaged three to four meters. These creatures come in three different morphologies centered around differences in their skulls due to changes related to feeding and habitat. Interestingly enough, modern crocodiles also share diverging morphological characteristics: compare the broad-snouted alligator and the long-snouted gavial. 

The Dolichorostral Morphology contains the ‘long snouted’ phytosaurs. These organisms had a long, slender snout with homodont conical teeth (homodont meaning that all teeth were the same). These phytosaurs were most likely piscivores (fish eaters) and were adapted to seize fast aquatic prey. However, they wouldn’t have fared well against land-dwelling prey, unlike their brachyrostral cousins. Long-snouted phytosaur species include Paleorhinus, Rutiodon, and Mystriosuchus (the latter of which became almost fully aquatic with paddle-like limbs and a laterally-compressed tail used for marine locomotion). 

a school of Mystriosuchus hunting in the Late Triassic seas

The Brachyrostral Morphology contains the ‘short snouted’ phytosaurs. These phytosaurs were adapted to hunting and eating terrestrial prey. They had massive, broad snouts and strong skulls and jaws. Their front teeth were prominent fangs, and their rear teeth were blade-like, designed for slicing food into easily-swallowed chunks. Though some short-snouted phytosaurs – such as Nicrosaurus and Smilosuchus – seemed more designed for life on land than in the water, many of its brethren likely hung around shorelines and watering holes to snatch unwary prey coming to the water to drink – much like modern crocodiles in Africa. 

a pair of Smilosuchus prowling a herd of Placerias

The Altirostral Morphology contains the ‘high snouted’ phytosaurs. These are viewed as intermediates between the long-snouted and short-snouted phytosaurs. Their teeth were heterodont (not all alike), but they weren’t as developed as those of their short-snouted cousins. The ‘hybrid’ morphology may indicate a ‘generalist’ feeding style, in which they would prey on marine creatures as well as smaller terrestrial ones. An example of this morphology is the phytosaur Pseudopalatus.

a Rutiodon growls at a flock of Fabrosaurus

The three main morphologies aside, all these phytosaurs have at least one thing in common: were we to step back in time today, our gut instinct would tell us they were crocodiles. Nevertheless, they were not crocodiles and not even ancestral to them. There are several key differences between phytosaurs and crocodiles. Phytosaurs had primitive ankles, and they lacked the bony secondary palate that enables crocodiles to breathe even when their mouths are full of water (though some scientists speculate they had a fleshy palate rather than a bony one, as many Mesozoic crocodiles are thought to have had). Phytosaurs were more heavily armored than crocodiles: phytosaurs were protected by heavy bony scutes, and their bellies were reinforced with a thick arrangement of abdominal ribs called gastralia. Crocodile nostrils are placed near the end of the snout, but phytosaur nostrils were placed on a crest high on the skull near or above the eyes (presumably to enable them to breathe while they floated just underneath the surface of the water). And, unlike crocodiles, phytosaurs had an erect gait with their legs positioned directly beneath their bodies rather than sprawled to the side. Thus phytosaurs could move easily about on land, though they were at home in the water, too; phytosaur ‘swim tracks’ have been found in the fossil record. Though it’s likely that they reproduced the same way as modern crocodiles – laying eggs – no nests have been found. Some paleontologists speculate that phytosaurs provided parental care for their young like modern crocodilians.