PalQuiz 3

Here are the answers to the second quiz:

1. Gallimimus is a theropod, the group containing the meat-eating dinosaurs. However, Theropoda also includes some herbivorous dinosaurs, and some groups where the experts disagree about whether they were (predominantly) carnivorous or herbivorous. Gallimimus belongs to the ornithomimid family (so, if you answered B on this question, it is understandable – you fell into my trap – but the ornithopods were a completely different group, including the duck-billed dinosaurs) within the theropod group; many paleontologists have begun to change their views on the feeding habit of this peculiar group: more and more evidence point toward them not being efficient predators, and that they perhaps were mostly plant-eaters. It is indeed a quite intriguing group when you look into it in more detail. Ornithomimdae basically means ‘bird mimic’, and the emphasis is on the word mimic: they are not birds, but very similar in many respects, although their lineage did not give rise to the birds. Gallicusaurus is completely made up…

2. ‘Mammal-like reptiles’ is the colloquial term for the synapsid group – the ‘reptiles’ that were intermediate between ‘reptiles’ and mammals. I put ‘reptiles’ within inverted commas because it is a group that is vanishing from formal use, because scientists have realised that the grouping is chaotic and there is little that unifies them as a group without including non-‘reptiles’. Diapsids are a group that includes most of what we mean by the colloquial term ‘reptiles’ (excluding turtles, but including birds), but none of these were ‘mammal-like’. Cynodonts are indeed a type of advanced synapsids, but all ‘mammal-like reptiles’ are not cynodonts, so B is incorrect. Mammoreptilians is just another word I made up…

3. This was a real tricky question, which I suspect is impossible to figure out if you have not seen an echinoid – or sea urchin – without its spines before. Those knobs you see on the surface are where the spines are held in life. However, if you were aware that sea urchins are echinoderms, i.e. relatives of starfish, and that the group is distinguishable by its five-fold symmetry, you may have noticed that the surface if divided into five plates, each with two parallel rows of spine attachment sites (if you had counted only the spine rows, you would have made out ten, which is divisible by five, so there is a five-fold symmetry). However, I made this one level trickier: both C and D were different types of sea urchins: regular and irregular. This one s a regular echinoid, a form with the mouth facing downward (though that is not easy to see on the picture, I give you that) and a nearly perfectly spherical shell; irregular echinoids have more elongate shells (and shorter spines), because they live as burrowers, so a narrower shape is easier to dig down in the sea bottom.

Picture from here.

Here are some drawings of irregular echinoids, from here.

4. The oldest known land plants appeared in the late Ordovician period, about 450 million years ago, the earliest of the options. They don’t seem to have made much fuss during the following Silurian period, but in the Devonian (when they evolved to be able to grow far away from large water bodies), they spread quickly and widely across land. The next period, the Carboniferous, is known for its vast swamp forests, from which most of our fossil fuels are taken. However, they all originated much earlier, in the Ordovician.

5. Test is the more formal word for the invertebrate shell. Carapace is the shell of turtles, so it could easily be confused. Tectum sounds like it could be an actual latinate term, but I do not know what it would mean in that case… The same goes for urca.

Now, over to the questions for this time.

1. In his book The Dinosaur Heresies (1986), the paleontologist Robert T. Bakker proposed several highly controversial theories about dinosaurs, but was not taken seriously until many years later. Why?

i. He presented poor evidence

ii. His arguments were highly biased

iii. The ‘orthodox’ authorities at that time were too stubborn and close-minded to change their world view

iv. Heredity was no understood at that time

A. i only

B. i and ii

C. iii only

D. All of the above

2. What type of marine organism is this?

 

A. Kelp

B. Sea tulip

C. Crinoid

D. Sea anemone

3. What does the idea of dinosaurs having feathers strongly suggest?

i. They were active animals

ii. They were nocturnal (night-hunting) animals

iii. They could fly

iv. They could see in colour

A. i only

B. iii only

C. ii, iii and iv

D. i and iv

4. Paleontology is…

A. The study of past life

B. The study of fossils

C. The study of extinct organisms

D. The study of fossilised past life

5. What do paleontologists examine?

i. Fossils

ii. Climate

iii. Rocks

iv. Decaying organisms

v.  Living organisms

A. i only

B. i and iii

C. i, iv and v

D. All of the above