nautiloids and ammonoids

Question 1

nautiloid and ammonoid SUB CLASS

Answer 1

cephalopoda

Question 2

cephalopoda SUB CLASS belongs to which PHYLUM?

Answer 2

mollusca

Question 3

modern day examples of cephalopods

Answer 3

squid, cuttlefish and octopus

Question 4

is nautilus alive now?

Answer 4

yes

Question 5

are ammonites alive now

Answer 5

no

Question 6

what is a protoconch

Answer 6

1st chamber occupied by juvenile

more chambers are added on as it grows

Question 7

what is the septum

Answer 7

the wall which closes off the body chamber as the animal grows

Question 8

what were the tentacles (nautiloid) for?

Answer 8

catching prey and movement

Question 9

what is the septal neck

Answer 9

an extension of the septum protruding backwards towards the protoconch in nautilus
points away from protoconch in ammoites

Question 10

what is the body chamber?

Answer 10

last and largest chamber housing most of the soft tissue

Question 11

what are the 3 tpes of coiling?

Answer 11

involute
evolute
planispiral

Question 12

what is involute coiling

Answer 12

inner coils are almost hidden by the last one

Question 13

where can you see involute coiling

Answer 13

nautlilus

Question 14

what is evolute coiling

Answer 14

earlier coils can be seen

wide umblilicus

Question 15

where is evolute coiling common

Answer 15

ammonoids

Question 16

what is plainspiral coiling

Answer 16

shell coiled in a single plane

Question 17

what is the umbilicus

Answer 17

diameter of depression between the inside margins of the coil

Question 18

what is AMMONOID morphology

Answer 18

evolute coiling
some have a keel (ridge along the middle for balance)
septal neck points away from protoconch

Question 19

what is NAUTLOID mode of life

Answer 19

nektonic - lived in water column

Question 20

what is the siphuncle

Answer 20

tube passing through septal neck which interconnects chambers
controls gas and water level to control BOUYANCY

Question 21

NEKTONIC ammonoid/nautiloid (LATERAL MOEVEMNT) mode of life

Answer 21

lateral movement
tentavles used to swim in water column
jet propulsion where water is expelled from the ‘funnel’ to push ammonoid (usssually backward but can be aimed)

Question 22

NECKTONIC ammonoid/nautilus (vertical)

Answer 22

empty chambers have mixture of gas and water
(gas is N rich)
levels adjust to make creature float upward/downward

Question 23

HUNTER killer cephalopod

Answer 23

evidence suggests they were predators

Question 24

spetal necks point towards or away from protoconch AMMONITE

Answer 24

away from protoconch

Question 25

septal neck points towards or away from protoconch in NAUTILUS

Answer 25

towards protoconch

Question 26

is siphuncle central in nautilus

Answer 26

yes

Question 27

is siphuncle central in ammonoid

Answer 27

no, close to outer edge

Question 28

simple to complex sutre lines

Answer 28

nautilus (simple)
gonatitic
ceratitic
amonitic (complex frilly)

Question 29

which had v complex sutre line

Answer 29

ammonoid

Question 30

which had simple sutre

Answer 30

nautilus

Question 31

which was more complex sutre ceratitic or goniatitic

Answer 31

ceratitic

Question 32

which was second most complex sutre

Answer 32

ceratitic

Question 33

which was second most simple sutre

Answer 33

goniatitic

Question 34

goniatite range

Answer 34

Devonian - permian

Question 35

ceratite range

Answer 35

Triassic - jurassic

Question 36

ammonite range

Answer 36

Jurassic - cretaceous

Question 37

nautiloid range

Answer 37

Cambrian - present

Question 38

how did they all evolve from nautilus

Answer 38

nautlius eveolved in Cambrian, evolved into goniatite -. ceratite and ammonite.