1
00:00:01,840 --> 00:00:07,920
Speaker 1: Welcome to Brainstuff, a production of iHeartRadio, Hey Brainstuff. Laurin

2
00:00:07,960 --> 00:00:12,920
Speaker 1: Vogelbaum here. If you're like me, you've never really thought

3
00:00:12,920 --> 00:00:15,600
Speaker 1: about whether or not Tyrannosaurus rex might have been a

4
00:00:15,640 --> 00:00:20,360
Speaker 1: good kisser. Depictions of the so named tyrant lizard king

5
00:00:20,760 --> 00:00:24,960
Speaker 1: a typically fixture a veritable phalanx of teeth protruding from

6
00:00:24,960 --> 00:00:28,040
Speaker 1: its mouth even when its mouth is closed. It's an

7
00:00:28,080 --> 00:00:31,720
Speaker 1: image made famous by the Jurassic Park movies. Think of

8
00:00:31,800 --> 00:00:36,839
Speaker 1: that creepy crocodilian grin as it's hunting Doctor Grant, or

9
00:00:37,120 --> 00:00:40,400
Speaker 1: you if you've been on the theme park ride. But

10
00:00:40,520 --> 00:00:45,280
Speaker 1: that image might not be accurate after all. A study

11
00:00:45,320 --> 00:00:47,760
Speaker 1: published in March of twenty twenty three in the journal

12
00:00:47,880 --> 00:00:51,760
Speaker 1: Science postulates that the t rex and its fellow therapod

13
00:00:51,840 --> 00:00:56,600
Speaker 1: dinosaurs actually did have lips that covered their teeth, more

14
00:00:56,640 --> 00:01:02,200
Speaker 1: like modern lizards than crocodilians. A paleo Artists have often

15
00:01:02,240 --> 00:01:06,160
Speaker 1: depicted therapod dinosaur mouths as similar to those of alligators

16
00:01:06,160 --> 00:01:11,399
Speaker 1: and crocodiles, with enormous teeth protruding yet by comparing the

17
00:01:11,520 --> 00:01:14,720
Speaker 1: ratio of tooth size to skull length with that of

18
00:01:14,760 --> 00:01:18,400
Speaker 1: lizards like the komodo dragon. The researchers behind the study

19
00:01:18,480 --> 00:01:22,039
Speaker 1: concluded that t rex teeth weren't necessarily too big to

20
00:01:22,080 --> 00:01:27,240
Speaker 1: be covered by dino lips. The authors bolstered their claim

21
00:01:27,319 --> 00:01:29,520
Speaker 1: by comparing the teeth of a close relative to the

22
00:01:29,520 --> 00:01:33,320
Speaker 1: t rex, the Displetosaurus, with those of an American alligator.

23
00:01:34,360 --> 00:01:37,200
Speaker 1: While the enamel on the outer side of an alligator's

24
00:01:37,200 --> 00:01:40,399
Speaker 1: teeth tends to wear down pretty quickly due to exposure

25
00:01:40,400 --> 00:01:43,920
Speaker 1: to the elements, the enamel of the dinosaur's tooth evidenced

26
00:01:44,040 --> 00:01:47,880
Speaker 1: no such pattern. This suggests the possibility that its teeth

27
00:01:47,920 --> 00:01:52,840
Speaker 1: were protected behind lips. The last piece of evidence the

28
00:01:52,880 --> 00:01:56,360
Speaker 1: study relied on is the similarity between certain features of

29
00:01:56,400 --> 00:02:00,720
Speaker 1: therapod dinosaur skulls and the skulls of lipped lizards like iguanas.

30
00:02:01,680 --> 00:02:05,680
Speaker 1: A lipless crocodiles and alligators have small pores over their

31
00:02:05,840 --> 00:02:09,919
Speaker 1: entire snouts that contain nerves sensitive to touch, heat, cold,

32
00:02:09,960 --> 00:02:15,320
Speaker 1: and certain chemicals in their environments. Meanwhile, lizards like iguanas

33
00:02:15,360 --> 00:02:19,120
Speaker 1: have a row of larger holes called foramina, aligned above

34
00:02:19,120 --> 00:02:23,280
Speaker 1: their teeth that contain nerves and blood vessels. A therapod

35
00:02:23,320 --> 00:02:27,360
Speaker 1: dinosaur skulls are more similar to the lizards, suggesting that

36
00:02:27,400 --> 00:02:31,080
Speaker 1: their facial structures were closer to that of lizards with lips,

37
00:02:33,280 --> 00:02:39,399
Speaker 1: so case closed. As with everything dinosaur related, paleontologists draw

38
00:02:39,440 --> 00:02:43,960
Speaker 1: their conclusions based on ancient and incomplete data, and other

39
00:02:44,080 --> 00:02:48,120
Speaker 1: dinoscholars aren't so sure about this whole t Rex lips situation.

40
00:02:49,800 --> 00:02:53,840
Speaker 1: One Thomas Carr, a vertebrate paleontologist who has studied therapod

41
00:02:53,919 --> 00:02:58,079
Speaker 1: facial structure, told Science that he didn't find the study persuasive.

42
00:02:59,040 --> 00:03:03,079
Speaker 1: His own findings indicate that theropods snouts were tough, scaly,

43
00:03:03,320 --> 00:03:06,520
Speaker 1: and devoid of soft tissue, and thus when it comes

44
00:03:06,520 --> 00:03:11,919
Speaker 1: to lips more closely resembled crocodile snouts. It's also unclear

45
00:03:12,000 --> 00:03:15,080
Speaker 1: whether exposure to the elements would have meaningfully damaged the

46
00:03:15,160 --> 00:03:18,480
Speaker 1: teeth of t Rex. If the skeptics are correct, t

47
00:03:18,639 --> 00:03:22,239
Speaker 1: Rex might have been perpetually smiling for the camera. After all,

48
00:03:24,360 --> 00:03:27,640
Speaker 1: a new evidence is always being investigated. This won't be

49
00:03:27,680 --> 00:03:30,959
Speaker 1: the first time that paleontologists and paleo artists have revised

50
00:03:31,000 --> 00:03:33,480
Speaker 1: their working draft of what the t rex's mouth looked like,

51
00:03:33,639 --> 00:03:37,360
Speaker 1: and it probably won't be the last. In the nineteen

52
00:03:37,400 --> 00:03:40,920
Speaker 1: twenties and thirties, for example, t Rex was often depicted

53
00:03:40,960 --> 00:03:44,960
Speaker 1: with lips, and until we found a mummified fossil of

54
00:03:45,000 --> 00:03:48,160
Speaker 1: a t rex skull, we won't know for sure. We

55
00:03:48,240 --> 00:03:51,600
Speaker 1: haven't even found any with skin patterning intact, so there's

56
00:03:51,640 --> 00:03:54,520
Speaker 1: a possibility that t Rex had feathers like some of

57
00:03:54,560 --> 00:04:02,440
Speaker 1: its smaller relatives. Today's episode is based on the article

58
00:04:02,680 --> 00:04:05,200
Speaker 1: t Rex didn't Kiss and Tell, but may have had

59
00:04:05,280 --> 00:04:08,360
Speaker 1: lips on how Stuffworks dot Com, written by Thomas Harlander.

60
00:04:08,920 --> 00:04:11,400
Speaker 1: The brain Stuff is production of iHeartRadio in partnership with

61
00:04:11,440 --> 00:04:13,880
Speaker 1: how Stuffworks dot Com and is produced by Tyler Klang.

62
00:04:14,440 --> 00:04:17,760
Speaker 1: For four more podcasts from iHeartRadio, visit the iHeartRadio app,

63
00:04:17,880 --> 00:04:20,800
Speaker 1: Apple Podcasts, or wherever you listen to your favorite shows.