Tyrannosaurus rex: what we really know, from teeth and dung to tiny arms

Tests: 5 of 12 right · Exam: 2 of 4 right · Kind: plain · Understood: 11 of 16 · Run: 2026-10-18, commit f3c23ea72

Lesson 265 of the biology course of Mova's primary school, as Mova's small model took its tests: it had read this lesson and the ones before it and learned from their exercises. Each test shows the options in the order the student saw them, its choice, the right answer, the score of every option and why it chose. The lesson itself, sentence by sentence with trees and pragmatics: the lesson in the corpora.

Every question of this lesson and each of its options parsed by Mova, with trees and pragmatics: the lesson's questions in the corpora.

Test 1 · right ✓

«my cousin says T. rex had massive teeth for eating leaves, that's why they're so big» What is right?

1. No, T. rex had no teeth, only a beak — score 3
2. Yes, T. rex only ate leaves and fruit — score 5
3. No, its thick teeth were for crushing bone and meat — ← Mova's choice · ✓ the right answer · score 6
4. Yes, big thick teeth are the best ones for chewing leaves — score 5

Why: It took the question to ask why something happens (its cause). It chose option 3 with score 6, against 5 for the next best. Its support: lesson 265, line 8: «T. rex teeth were made to crush bone, and its bite was many times stronger than a lion's.», reached through the option's own match among the sentences about the question's things. What matched: the same action «crush» (+3); the same thing acted on «bone» (+3). · the question and its options parsed, with trees and pragmatics

Test 2 · wrong ✗

In a film a T. rex chases a jeep at top speed and nearly catches it. What is closer to the truth?

1. A T. rex could fly right over the top of the jeep — no support
2. A grown T. rex was too heavy to run that fast — ✓ the right answer · score 3
3. A T. rex could only crawl on its belly — no support
4. A T. rex could run much faster than any car — ← Mova's choice · score 6

Why: It took the question to ask which statement is true. It chose option 4 with score 6, against 3 for the next best. Its support: lesson 265, line 4: «Films like to show a T. rex racing a jeep and missing you if you stand still, but its heavy legs could not sprint, and its big forward-facing eyes and keen nos…», reached through the option's own match among the sentences about the question's things. What matched: the same action «race» (+4); the same doer «t. rex» (+2). The right option, 2, scored 3. · the question and its options parsed, with trees and pragmatics

Test 3 · wrong ✗

«stand still mate, it can't see you if you don't move!!» Is that right?

1. No, because T. rex was totally blind — ← Mova's choice · no support
2. No, T. rex had good eyes and a keen nose — ✓ the right answer · no support
3. Yes, but only at night — no support
4. Yes, it only saw moving things — no support

Why: No option found support in what it remembers, so it guessed: it took the first option shown. · the question and its options parsed, with trees and pragmatics

Test 4 · right ✓

A cartoon dinosaur film shows T. rex and Stegosaurus fighting. What is wrong with that?

1. Stegosaurus was much bigger and stronger than T. rex — score 3
2. They were the same animal with two names — no support
3. T. rex was far too small to fight a Stegosaurus at all — no support
4. They lived about 80 million years apart and never met — ← Mova's choice · ✓ the right answer · score 6

Why: It took the question to ask which statement is true. It chose option 4 with score 6, against 3 for the next best. Its support: lesson 265, line 6: «T. rex lived about 68 to 66 million years ago in western North America and was one of the last big dinosaurs.», reached through the option's own match among the sentences about the question's things. What matched: the same action «live» (+4); the same doer «t. rex» (+2). · the question and its options parsed, with trees and pragmatics

Test 5 · wrong ✗

Count them: a museum hall has 3 T. rex skeletons. How many legs, arms and tails is that in all?

1. 3 legs, 6 arms and 3 tails — ← Mova's choice · no support
2. 6 legs, 6 arms and 3 tails — ✓ the right answer · no support
3. 12 legs, 3 arms and 3 tails — no support
4. 6 legs, 3 arms and 6 tails — no support

Why: No option found support in what it remembers, so it guessed: it took the first option shown. · the question and its options parsed, with trees and pragmatics

Test 6 · wrong ✗

«lol T. rex with them tiny useless arms, couldn't even scratch its nose» What is true?

1. Its arms fell off as it grew up — ← Mova's choice · score 6
2. Its arms were longer than its legs — no support
3. Its arms were short but strong, and scientists still argue what they were for — ✓ the right answer · no support
4. Its arms were useless, very weak and could not even lift a feather — no support

Why: It took the question to ask which statement is true. It chose option 1 with score 6, the only option with support. Its support: lesson 265, line 5: «Bones even have growth lines like the rings in a tree, and they tell us a T. rex grew up fast as a teenager and lived to about 28 to 30 years.», reached through the option's own match among the sentences about the question's things. What matched: the same action «grow up» (+4); the same doer «t. rex» (+2). The right option, 3, found no support in what it remembers. · the question and its options parsed, with trees and pragmatics

Test 7 · right ✓

Why is fossil dung so useful to scientists?

1. It shows what the animal really ate — ← Mova's choice · ✓ the right answer · no support
2. It shows how fast the animal ran — no support
3. It shows what colour the animal was — no support
4. It shows how loud the animal roared — no support

Why: No option found support in what it remembers, so it guessed: it took the first option shown. · the question and its options parsed, with trees and pragmatics

Test 8 · wrong ✗

A T. rex in a cartoon opens its mouth and roars like a lion. What do scientists think?

1. It sang like a songbird — no support
2. It roared exactly like a lion, and scientists have recordings of the sound — ← Mova's choice · score 8
3. Nobody knows its voice; it may have rumbled with its mouth shut like birds and crocodiles — ✓ the right answer · score 8
4. It squeaked like a mouse — no support

Why: It took the question to ask what it is done to. It chose option 2 with score 8, tied with another option at 8 (the first shown, or the one claiming less beyond what it knows, wins). Its support: lesson 124, line 8: «A lion's roar can be heard about 8 kilometres away; lions roar to claim their land and keep in touch, and a cub only starts real roaring at about one year old.», reached through the option's own match among the sentences about the question's things. What matched: the same action «roar» (+4); the same circumstance (+2); a different doer (counts against) (+2). The right option, 3, scored 8. · the question and its options parsed, with trees and pragmatics

Test 9 · wrong ✗

Why is a nearly whole skeleton like Sue such a treasure?

1. It is the only T. rex that has ever been found anywhere — ← Mova's choice · score 4
2. It was found alive — score 2
3. It still had all its skin and its eyes — score 2
4. Most dinosaurs are known only from a few bones — ✓ the right answer · score 2

Why: It took the question to ask why something happens (its cause). It chose option 1 with score 4, against 2 for the next best. Its support: lesson 28, line 1: «A shark is a fish with no bones at all: its skeleton is cartilage, the bendy stuff in your nose and ears, so it is light and flexible, and because cartilage ro…», reached through the cause of the sentence the question matched. What matched: the same light verb (be, have, do, get, go) (+2); the same doer «skeleton» (+1); a different thing acted on (counts against) (+1). The right option, 4, scored 2. · the question and its options parsed, with trees and pragmatics

Test 10 · right ✓

«so did T. rex have feathers or not, just tell me» What is the honest answer?

1. It had smooth skin with no scales at all — no support
2. Skin prints show scales on parts of grown ones, though babies may have been fluffy — ← Mova's choice · ✓ the right answer · score 19
3. It had thick fur like a woolly mammoth — no support
4. It was covered all over in long colourful feathers, like a giant parrot — no support

Why: It took the question to ask what is done. It chose option 2 with score 19, the only option with support. Its support: lesson 265, line 15: «Skin prints show small scales on parts of T. rex, while some smaller relatives such as Yutyrannus had feathers; babies may have been fluffy, but this is not kn…», reached through the same lesson line as the sentence the question matched. What matched: the same thing acted on «small scales» (+5); the same doer «skin prints» (+4); it fills the role the question asks for (+4); the same action «show» (+3). · the question and its options parsed, with trees and pragmatics

Test 11 · wrong ✗

What would happen if a grown T. rex walked into your school yard?

1. It would fit under a table — score 3
2. It would be no taller than a pony — score 3
3. Its hips would be as high as a double-decker bus — ✓ the right answer · no support
4. It would be much taller than a skyscraper in a big city — ← Mova's choice · score 5

Why: It took the question to ask what happens next. It chose option 4 with score 5, against 3 for the next best. Its support: lesson 265, line 6: «T. rex lived about 68 to 66 million years ago in western North America and was one of the last big dinosaurs.», reached through what followed the sentence the question matched. What matched: the same doer «t. rex» (+3); the same light verb (be, have, do, get, go) (+2). The right option, 3, found no support in what it remembers. · the question and its options parsed, with trees and pragmatics

Test 12 · right ✓

A T. rex was about 29 when it died. What did its bones show?

1. Growth lines that can be counted like tree rings — ← Mova's choice · ✓ the right answer · score 3
2. That it was still a baby — no support
3. Nothing at all, because age cannot be known from bones — score -1
4. Its exact age written in numbers on its teeth — no support

Why: It took the question to ask what it is done to. It chose option 1 with score 3, against -1 for the next best. Its support: lesson 265, line 5: «Bones even have growth lines like the rings in a tree, and they tell us a T. rex grew up fast as a teenager and lived to about 28 to 30 years.», reached through the option's own match among the sentences about the question's things. What matched: the same circumstance (+2); it fills the role the question asks for (+1). · the question and its options parsed, with trees and pragmatics

Exam question 1 · formal language · right ✓

Identify the principal purpose for which the teeth of Tyrannosaurus rex were adapted.

1. The grinding of vegetation — no support
2. The cracking of seeds and nuts — no support
3. The crushing of bone and the tearing of flesh — ← Mova's choice · ✓ the right answer · score 5
4. The filtering of water — no support

Why: It took the question to ask which statement is true. It chose option 3 with score 5, the only option with support. Its support: lesson 265, line 8: «T. rex teeth were made to crush bone, and its bite was many times stronger than a lion's.», reached through the same lesson line as the sentence the question matched. What matched: the same thing acted on «bone» (+3); the same action «crush» (+2). · the question and its options parsed, with trees and pragmatics

Exam question 2 · formal language · right ✓

Select the response consistent with the established facts concerning the speed of an adult Tyrannosaurus rex.

1. It is understood to have been incapable of true rapid running on account of its great mass — ← Mova's choice · ✓ the right answer · no support
2. It is understood to have been entirely immobile — no support
3. It is understood to have been the swiftest of all dinosaurs — no support
4. It is understood to have exceeded the speed of a motor vehicle travelling upon a modern road — no support

Why: No option found support in what it remembers, so it guessed: it took the first option shown. · the question and its options parsed, with trees and pragmatics

Exam question 3 · formal language · wrong ✗

Ascertain the nature of a coprolite, as the term is employed in palaeontology.

1. A fossilised tooth — ← Mova's choice · no support
2. A fossilised egg — no support
3. A fossilised footprint — no support
4. Fossilised dung — ✓ the right answer · no support

Why: No option found support in what it remembers, so it guessed: it took the first option shown. · the question and its options parsed, with trees and pragmatics

Exam question 4 · formal language · wrong ✗

Which of the following statements most accurately characterises the chronological relationship between Stegosaurus and Tyrannosaurus rex?

1. They were contemporaries inhabiting the same region — score 2
2. They were separated by no more than a few centuries — ← Mova's choice · score 4
3. They were separated by a greater span of time than that separating Tyrannosaurus rex from the present day — ✓ the right answer · score 3
4. Stegosaurus succeeded Tyrannosaurus rex by some millions of years — score -2

Why: It took the question to ask who or what does it. It chose option 2 with score 4, against 3 for the next best. Its support: lesson 265, line 16: «Stegosaurus lived about 150 million years ago, so more time separates Stegosaurus from T. rex than separates T. rex from us.», reached through the remembered sentence the question matched. What matched: the same action «separate» (+2); the same thing acted on «t. rex» (+2). The right option, 3, scored 3. · the question and its options parsed, with trees and pragmatics

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