Maiacetus Inuus: A New Transitional fossil Of The Whale Lineage

Whale evolution is something that I have blogged on before. This paper describes the discovery of yet another transitional fossil between artiodactyls and whales. The new species is called Maiacetus inuus, which means mother whale of inuus ( Inuus being the Roman god of fertility). It is so called, because one specimen was pregnant (the foetus is the blue shaded object below). What is interesting is that it is in a head down position; modern whales give birth tail first. This suggests that birth still took place on land. Not surprisingly, it is found in the right part of the world to be an intermediate form (Pakistan) and its morphology dates to the correct era too; 47.5 million years old. This makes it older than the more whale like Basilosaurids, and younger than the more primitive Ambulocetus, Indohyus and Pakicetids.

Compsognathus Longipes's Last Supper

OK, one final dinosaur post for the weekend. In the poo post, the implication of carnivory for “ original sin” was touched upon. I never tire of laughing at this article written by everyone’s’ favourite bearded cleric, where he thinks tsunamis, volcanic eruptions and death are the result of eating an apple. I particularly love the paragraph that starts off saying that atheists are becoming more frustrated as our aguments are shown to be limited - he then goes off on a truley ignorant rant of biblical proportions - and he claims to accept evolution, which makes his ignorance all the more incredible. It is a common belief that I don’t think many Christians think about seriously enough. Anyway, here is another example of carnivorous behaviour before the arrival of man. It is a drawing of the rib cage of Compsognathus longipes. Inside, a small skeleton of Bavariasurus (in darker shading) can clearly be seen. It appears to be swallowed whole.

Young earth creationists have to deny this comes before man and claim it ate it’s meal after man and woman sinned. However, let’s ignore the serrated teeth that are so good for hunting for a moment and ask why Elephants or squirrels don’t bring down lions and eat them. Could it be because they are not adapted to be hunters? Theists who accept evolution are confronted with the only credible alternative: god caused large scale industrial suffering to bring his “flawed” masterpiece into being.

Finally, to both sides: a challenge – show some evidence that 1) man existed with dinosaurs and explain the consilient nature of fossil dating techniques, or 2) a role for god in directing evolution that meets the standards of a scientific theory.

T. Rex, Warrior Or Wimp?

I linked to part of this program on the feeding behaviour of Tyrannosaurus rex in the previous post, but it is worth a view in its entierty.

Incidentally, David Houston was one of my Zoology lecturers

Jumbo Dinosaur Jobbies

Having a degree in Parasitology tends to familiarise you with the value of Jobbies; as one of my tutors said, “shit is tour bread and butter as a parasitologist”. This is because many parasites produce cysts or lay eggs that pass out the body in the faeces. These infect the next host and this spreads the disease. The eggs are often characteristic to a particular species or genus. So, you can work out infection rates and parasite loads of particular species in individual hosts. One quarter of the world population is infected by just one parasite – Ascarais lumbricoides. One of my class mates became infected with this and the first she knew of it was when she saw 20 one foot long worms thrashing in the toilet bowl. If you want to feel uncomfortable (or lucky) check out this picture out of someone who has just been "wormed"
Another thing that shit can tell you about diet. I remember one gross practical class where we had to sift through someone’s fudge. It was supposedly collected in the Dominican republic, but contained saw dust- turns out, it had been supplemented with veterinary material. What I remember most though is the huge chunk of onion in it. The person obviously ate onions, but didn’t chew properly or process their food that much either (probably the prof). Apparently, the prof had just discovered that not processing food properly can contribute to severe malnutrition in areas where intestinal parasites are prevalent. He found lots of unprocessed and therefore indigestible corn in the crap.

So, shit can tell you a lot about living animals. Now, to the main point of the post – dino poo. Fossil jobbies are called coprolites. We know for example that pines were on the menu of some dinosaurs, and they were clearly capable of grinding it down – as would be inferred from the structure of the teeth batteries of some herbivores. What is particularly interesting though is the Jumbo Jobbie shown below. It is a possible Tyrannosaurus turd, and measures about 17 inches long.

This majestic Bondi cigar even contains bone fragments belonging to a sub adult herbivore. The large quantity of bone in the meal suggests that the dinosaur was not careful about butchering its meal. We know that Tyrannosaurs were capable of biting through bone, as fossils showing pre-mortem Tyrannosaur bites have been found. These include Hadrosaurs with “healed” wounds that were excised by T. rex bites (about 4 minutes in), and even a T. rex with another T. rex’s tooth embedded in its rib- with an abscess formed around it. Those wanting a laugh (or to annoy themselves) should listen to creationist nincompoop Ken Ham’s short talk on the matter here. I don’t know which is the bigger pile of shite, but at least he knows the consequences of a meat eating dinosaur for his creationist myth that all animals ate fruit and veg before two mythical human beings ate a mythical fruit, and that supposedly caused death, volcanoes, earthquakes and the Mc Chicken Sandwich. That’s why he has to deny evolution. I touch on the absurdity of this claim here (incidentally, that is a Carcharodontosaurus skull at the top of the page).

The other thing that I want to mention is that parasite eggs have been found in fossil shit too (below from left to right Entamoeboides cyst, and two Ascarid eggs). I find this fascinating, and it tells us something about the health of these animals, as well as their ecological interactions with parasites. This is not the first time evidence has popped up for dinosaur parasite interaction, but is certainly the best – and all before man “polluted” creation – yet more evidence that the creationists need to go to farcical lengths to deny.

Finally, we know that some dung beetles even used dino poo – shit’s not that shit after all.

Archaeopteryx: The Most Beautiful Fossil Ever!

One of the most beautiful of fossils has to be the “Berlin specimen” of Archaeopteryx lithographica (below). This was discovered in the Solnhofen limestones in 1877, and dates to about 155 -150 million years ago (or 155 -150 million years BA* ). The first specimen was discovered in 1855 but its importance was not realised until 1970. When I first saw a picture of the Berlin specimen (probably about age 11) I became convinced about the truth of evolution. It is a wonderful example of a transitional form (or at least a close relative of one). This specimen clearly shows the presence of feathers on a very reptilian skeleton. There are reports that the specimen had a plume of feathers on its head, but these were lost during its preparation. Some specimens without the feathers preserved were once thought to be coelurosaurs. Given its importance, it is not surprising that creationists have to deny it is a transitional form. They have absurdly claimed that it is a fake (Even AIG has to admit nowadays that it is not). They desperately try to claim that it was a perching bird (with reptilian tail and teeth?). Hovever, a recently discovered specimen clearly shows that it was unable to perch (It did not have a reversed toe). Creationist even try and quote mine Alan Fedducia who claims birds are evolved from a non dinosaurian lineage. What they don’t mention is that Fedducia still believes they are transitional forms butt share a common ancestor with dinosaurs, rather than being descended from them. This theory has been pretty mush refuted nowadays. Creationists have also tried to push the idea that Protoavis was a primitive bird that lived about 70 million years before Archaeopteryx. Therefore it cant be the ancestor of birds.

There are a couple of problems with creationists using this line of argument. The first is that they deny conventional dating techniques are accurate – they cannot then claim anything about which specimen is oldest. Then, they say that Protoavis is more birdlike than Archaeopteryx. More bird like? That is like an admission of grades of “birdiness” – you know, the way that evolution works. Internal consistency is not something creotards are known for – they pick and choose as long as they can pretend that it agrees with the mutually exclusive accounts of genesis 1 and 2. Anyway, let’s go with the scientific ages. Is there a problem? I would say there are two good reasons why there is no problem. The first being that Archaeopteryx could be one of those long lived “transitional” forms we see today – like the lungfishes or coelacanths (note I am not saying these are transitional forms, but transitional like forms). The second and most probable case is that Protoavis is not a bird at all. The fossils that we have are very poorly preserved (many diagnostic bones are missing and the skulls are badly crushed (you know, all the usual complaints that creationists use when they need to deny something is a transitional form (see the Ambulocetus post). It is generally thought in the peer reviewed literature (enter creationist conspiracy theories) that Protoavis is actually not of the bird lineage.

So, what makes Archaeopteryx a transitional form? Features found in Dinosaurs (particularly the group called the Dromaeosaurs that includes Velociraptor) are tagged with a D and those found in birds are tagged with a B.

Skull

Contains teeth (like those of small theropods) (D)
Long external nostrils (B)
Nasal opening located at anterior of the snout and separated by large pre- orbital fenestra (hole) (D)
Nasal bones long and depressed (D)
The quadrate and quadratojugal (two upper jaw bones) are not sutured together (B)
Brain case intermediate in structure between birds and dinosaurs (B,D)
Palatine bone dinosaur shaped (D)
No bill (D)

Vertebrae

Neck vertebrae have concave articulations (D)
Neck S shaped (B,D)
Neck attaches to rear of skull (D)
Sacrum contains 6 vertebrae (D)
23 caudal (tail) vertebrae (D) However, this is a reduction in the total number comaired to other theropods (can number over 50). Birds have several that fuse to form the pygostyle (they are more reptilian during development).

Limbs and associated bones

Strap like scapula (shoulder bone) (B,D)
Fused V- shaped wishbone (essential for bird flight (B,D)
Rudimentary sternum (breast bone) This is essential for flight muscle attachment and is more dinosaur like (B,D)
C- shaped (semilunate) carpal (wrist bone). This is essential for bird flight (B,D).
Clawed manus (hand) (D). Interestingly, one modern bird (the Hoatzin) retains a rudimentary claw in the juvenile.
Pelvis dinosaur shaped (D)
Femur head is orthogonally turned (D)
Astralagus (ankle bone) has a process extending upwards into the tibia (a diagnostic characteristic of theropods) (D)
The feet are dinosaurian. Contrary to creationist claims, there is no reversed hallux (big toe) that allows perching (D)
The second toe is hyper flexible as in dromaeosaurs (D)

Other features

Numerous hollow bones (B,D)
The presence of feathers (B, D).

There are many more features that show the link between birds and dinosaurs. Cladistic analysis actually reveals Archaeopteryx to be more dinosaur than bird. This is only a small fraction from a single species. A list of other intermediates (some more bird like, others less so) can be found here.

*BA (years Before Apples) for those who believe that eating a fruit somehow caused death to enter the world (you know who I mean).

Transitional Fossils - The "Frogamander"

Transitional fossils are great. Darwin recognised their value when he lamented their scarcity:


“But as for this theory, innumerable transitional forms must have existed, why do we not find them embedded in countless numbers in the crust of the earth?” (Origin of species 1859).

Not surprisingly, creationists intentionally misuse this quote to claim such fossils do not exist and use Darwin as an argument from authority. Of course, only 4 years earlier, perhaps the most famous transitional fossil of all; Archaeopteryx lithographica was discovered, and the second specimen, now called the “London specimen” was discovered 3 years after the “Origin” was published. Their importance was not realised until later though, but every time a new transition is found, this prediction of Darwin’s is further confirmed. It also means creationists have to spend more and more time with their heads in the sand in denial, or spread lies about the nature of the fossil. Every now and then they concede that the fossil does display the characteristics of two related groups, but childishly claim that there are now two gaps that need to be filled – one before the transitional form and one after it. This truly is the stuff of desperation, and often these gaps are filled. Even worse for creationists though is the fact that we can predict where and in what age of rocks we will find transitional fossils of a particular lineage in – it’s called geographic distribution of lineages fundies!

Since Darwin commented on the rarity of transitional forms (150 years ago – take note fundies) hordes of transitional forms have been discovered. A small fraction of which are noted here. With every new transitional fossil, a further nail goes into the creationist coffin. Recently, a new one has been described that sorts out the evolution of frogs and salamanders. It had been suggested that frogs and salamanders evolved from a tetrapod group called the Temnospondyli. These are an ancient group that are found in early Permian rocks. This new specimen called Gerobatrachus hottoni has been dubbed a “frogamander” (pictured above) as it displays characteristics of frogs, salamanders and other Temnospondyls. Thanks to this fossil, we can also propose that frogs and salamanders diverged from each other some 240 and 275 million years ago.

More information can be found here.