Lecture 3 Flashcards
Agnathans through Labyrinthodonts
1
Q
traits of a vertebrate
A
all chordate traits, plus vertebrae, a cephalized brain, and neural crest
2
Q
when did animals first come about?
A
541 mil Years, Paleozoic
3
Q
The Burgess Shale Fauna
A
Fossil field in Canadian Rockies of British Columbia with exceptional preservation of soft body parts in black shale, date to 530 mya = Cambrian
Explosion – “rapid” (mya) appearance of animals
4
Q
Maotianshan Shales
A
Similar field; Chengjiang County, Yunnan Province Chin
5
Q
types of Agnatha
A
cyclostomes, craniates
6
Q
when was Agnatha
A
cambrian
7
Q
what are cyclostomes
A
lamprey and hagfish
8
Q
what do craniates have
A
cephalized and have some sort of skull (cartilage or bone)
9
Q
Extinct Agnathans
A
from early Cambrian
Haikouella - craniate like
Haikouichthys - craniate
10
Q
Early Vertebrates Were Agnathan ___ Feeders
A
Filter
11
Q
Big transitions in feeding modes
A
cilia-mucus,
muscular pump
-vertebrate-agnathan
filter feeders
12
Q
living agnathans
A
Hagfish (Myxinoidea) (they have knot-behavior when feeding… curl into a not or when you hold them) and
Lamprey (Petromyzontifomres)
13
Q
The relationship of cyclostomes to other vertebrates is agreed upon but
A
the relationship between hagfish and lamprey is not
14
Q
the relationship between hagfish and lamprey
A
The two possible ways in which cyclostomes are related to gnathostomes:
(a) they are “paraphyletic”, with lampreys being more closely related to gnathostomes than either is to hagfishes, or
(b) they are “monophyletic”, and hagfishes and lampreys are more closely related to each other than either is to gnathostomes.
15
Q
what does Agnatha mean
A
without jaws
16
Q
Class Myxini
phylum
subphylum
superclass
name
what do they have and lack
what are they known for
time
A
Phylum Chordata, Subphylum Vertebrata Superclass Agnatha
- hagfish
- myxomatosis means slime/mucous
- Notochord w/o vertebra, no bone, no jaws, no scales
- No lateral line system (internal nares)
- Detritus feeders
- Known for their slime
- Carboniferous to present
17
Q
what do lateral line systems do
A
Detects movement and electrical fields in water
18
Q
Class Petromyzoniformes
phylum
subphylum
superclass
meaning
what do they have and not have
feed
time
A
Phylum Chordata, Subphylum Vertebrata Superclass Agnatha
lamprey
- lambere = to lick
- petro = stone
- Notochord, has arcualia (cartilage), no bone, no scales
- lateral line present
- Some parasitic, others do not feed adults
- Devonian to present
19
Q
Class Conodonta
phylum
subphylum
superclass
A
Phylum Chordata, ~Subphylum Vertebrata
Superclass Agnatha
The Conodonts
(Gr. cono = cone, odont = teeth)
teeth (conodonts) - calcium phosphate (not bone)
Post-anal tail & myomeres, no gill slits (expect in one specimen), maybe a nerve cord, maybe a notochord
Fossils in Cambrian - Triassic
20
Q
Ostracoderms
phylum
subphylum
superclass
group of..?
what do they have
one type hass
time
A
Phylum Chordata, Subphylum Vertebrata
Superclass Agnatha
shell skins
Gr. ostracon = shell; derma = skin)
Paraphyletic group, of jawless fish covered with large bony plates
notochord with vertebral neural
arches only
Paired fins in one type only
Fossils in Cambrian - Devonian
21
Q
what does gnathans mean
A
jaws
22
Q
Class Placodermi
phylum
subphylum
superclass
what do they have
what do they not have
time
A
Phylum Chordata, Subphylum Vertebrata
Superclass Gnathostomata
Class Placodermi (placo = plate/flat stone)
Bony plates
“Invented” jaws
Paired fins, notochord with vertebral neural and hemal arches (no centrum)
Fossils in Silurian – Permian
23
Q
Class Chondrichthyes
phylum
subphylum
supere class
what do they have
two subclasses
what do they consist of
time
A
Phylum Chordata, Subphylum Vertebrata
Superclass Gnathostomata
vertebrae, lack bone – has cartilage (2º loss), placoid scales
Subclass Elasmobranchii
– (Gr. Elasmos = metal beaten out; branchia = gill)
- skates, rays, sharks
Subclass Holocephalii
– (Gr. Holo = complete; cephalic = head)
- chimeras
Devonian - present
24
Q
describe a skate
fins
swim
offspring
A
small fins on tail
swim by creating a wave and starts at head then ripples down rest of body
- oviparous (egg laying)
25
describe a ray
what do they have
swim
offspring
venomous barb or spines
- swims by moving finds up and down like a bird
- ovoviviparous - egg hatch within the body
26
Class Acanthodi
sister group
traits (3)
time
Phylum Chordata, Subphylum Vertebrata
Superclass Gnathostomata
(acanthos = spine)
Sister group to Osteichthyes
Distinctive spine in fins
Cartilaginous
Have scales more like those of bony fish
Fossils in Silurian - Permian
27
are acanthodian sharks?
Look like sharks - have cartilaginous endoskeleton
However, have scales more like boney fish (specifically rhomboid shaped ganoid scales similar to gar and Amia) and fins have a boney base with a dentine spine
28
Class Osteichthyes
skeleton
subclasses
time
Phylum Chordata, Subphylum Vertebrata
Superclass Gnathostomata
the bony fish (Gr. osteon = bone)
Bony skeleton primitive
Two subclass:
– *Subclass Actinopterygii (ray-finned fishes)
– *Subclass Sarcopterygii (lobe/fleshy-finned)
Devonian – present
29
Subclass Actinopterygii (ray-finned fishes)
what do they have
examples
Class Osteichthyes
Lungs or swim bladder
Lepidotrichia in fins
Scales
ex: amia, polypterus (diverse group)
30
Subclass Sarcopterygii
Class Osteichthyes
(sarc = flesh; pterygi = fin)
a.k.a Choanichthyes – (choan = funnel/internal nares)
Superorder Coelacanthiformes or Actinistia or Crossopterygii (krosso = fringe) = the coelocanths (mid-Devonian-present)
* *Superorder Dipnomorpha (early-Devonian-present) – Order Dipnoi (di = two; pneo = breath, air or lungs) having both gills & lungs
* *Superorder Rhipidistia (mid-Devonian) – all extinct, most closely related to coelacanths, ancestral to tetrapods
31
Sarcopterygians structure
multiple dorsal and ventral fins
32
Superorder Coelacanthiformes or Actinistia or Crossopterygii (krosso = fringe) = the coelacanths
No internal nares (lost), Thought to be extinct, Rediscovered, 1938, found off the east coast of South Africa, mid-Devonian-present
33
Superorder Dipnomorpha, Order Dipnoi
(di = two; pneo = breath, air or lungs) – gills & lungs)
Three extant genera
Devonian - present
in australia in turbid water, breathing air
in africa - estivate through dry season by burrowing in mud, slows its metabolism, less toxic urea (waste)
South America - found in swamps and slow moving waters, obligate air breather, burrows in mud, makes a chamber, leaving holes to the surface for air
34
Rhipidistians
how did they survive
Devonta era - tropical with seasonal droughts
ways to survive - move from dry areas to wetter areas
35
Superorder Rhipidistia
three traits
example
time
Phylum Chordata, Subphylum Vertebrata
Superclass Gnathostomata
Class Osteichthyes – the bony fish (Gr. osteon = bone)
Subclass Sarcopterygii
Paraphyletic group; all extinct, gave rise to tetrapods
* Internal nares, loss of median fin
* Fin elements correspond begin to resemble tetrapod limb bones (“pre-adaptation”)
* ex: Tiktaalik - shoulder girdle separate from skull
* Fossils in the Devonian – Early Permian
36
example of Rhipidistians
Eusthenopteron, Pandericthys, and Tiktaalik
37
what's special about Tiktaalik
NOTE SHOULDER GIRDLE! Looks very amphibian-like
38
Labyrinthodonts
special traits (4)
subclass
Fish with better “on land” crawling skills are
selected
* Traits associated with being better able to walk
on land:
– Loss of median fins
– Legs (from lobe fins)
– Scales reduced (greater body movement)
– Pelvic girdle attached to vertebral column (supports
body out of water)
– These traits are found in Subclass
Labyrinthodontia
39
Subclass Labyrinthodontia
class
alive?
gave rise to
whose ancestor
five traits
time
sister group
Phylum Chordata, Subphylum Vertebrata
Superclass Gnathostomata, Class Amphibian*
(labyrinth = maze, odont = teet)
All extinct, gave rise to amniotes (cotylossauria), our ancestors
* No median fins, scales reduced, have legs – likely crawled by lateral undulations
* Pelvic girdle attached to vertebral column
* Late Devonian
* Maze like pattern in teeth
* Sister group to Amphibia
40
examples of Labyrinthodonts
Acanthostega, Icthyostega, and Seymouria
41
what is special about Seymoria
NOTE Pectoral (not attached to skull) and pelvic girdles (attached to vertebral column)
42
Other Labyrinthodonts: Order* Temnospondyls
spine
relations
time
Vertebra divided in to multiple parts – separate pleurocentrum and intercentrum.
* Related or ancestral to modern Amphibians.
* Early Carboniferous (Mississippian) to early Cretaceous
43
class amphibia, subclass lepospondyls
loss
related acestral to who
vertebra
time
move from
Related or ancestral to all or some modern
Amphibians
* Loss of labyrinthodont teeth – 2o loss or not?
* Solid spool shaped vertebra with neural spine, two centrum
* Early Carboniferous to late Permian
* *More recently moved out of the Labyrinthodont group*
44
Modern day Amphibians + Labyrinthodonts are all in Class ___
Amphibian
45
Safe to say that modern anamniotes and amniotes come from ___
labyrinthodonts
46
Amphibians may be a ___ group
diphyletic
47
diphyletic
derived from two lines of evolutionary decent
48
More recently the field is leaning toward the idea of modern amphibians being descended from
temnospondyls alone rather than both temnospondyls and lepospondyls OR lepospondyls alone
49
Labyrinthodonts Gave Rise to
Cotylosaurs
50
Cotylosaurs
Loose term used to refer generally to basal amniotes
51
all chordate traits, plus vertebrae, a cephalized brain, and neural crest
traits of a vertebrate
52
541 mil Years, Paleozoic
when did animals first come about?
53
Fossil field in Canadian Rockies of British Columbia with exceptional preservation of soft body parts in black shale, date to 530 mya = Cambrian
Explosion – “rapid” (mya) appearance of animals
The Burgess Shale Fauna
54
Similar field; Chengjiang County, Yunnan Province Chin
Maotianshan Shales
55
cyclostomes, craniates
types of Agnatha
56
cambrian
when was Agnatha
57
lamprey and hagfish
what are cyclostomes
58
cephalized and have some sort of skull (cartilage or bone)
what do craniates have
59
from early Cambrian
Haikouella - craniate like
Haikouichthys - craniate
Extinct Agnathans
60
Filter
Early Vertebrates Were Agnathan ___ Feeders
61
cilia-mucus,
muscular pump
-vertebrate-agnathan
filter feeders
Big transitions in feeding modes
62
Hagfish (Myxinoidea) (they have knot-behavior when feeding... curl into a not or when you hold them) and
Lamprey (Petromyzontifomres)
living agnathans
63
the relationship between hagfish and lamprey is not
The relationship of cyclostomes to other vertebrates is agreed upon but
64
The two possible ways in which cyclostomes are related to gnathostomes:
(a) they are “paraphyletic”, with lampreys being more closely related to gnathostomes than either is to hagfishes, or
(b) they are “monophyletic”, and hagfishes and lampreys are more closely related to each other than either is to gnathostomes.
the relationship between hagfish and lamprey
65
without jaws
what does Agnatha mean
66
Phylum Chordata, Subphylum Vertebrata Superclass Agnatha
- hagfish
- myxomatosis means slime/mucous
- Notochord w/o vertebra, no bone, no jaws, no scales
- No lateral line system (internal nares)
- Detritus feeders
- Known for their slime
- Carboniferous to present
Class Myxini
phylum
subphylum
superclass
name
what do they have and lack
what are they known for
time
67
Detects movement and electrical fields in water
what do lateral line systems do
68
Phylum Chordata, Subphylum Vertebrata Superclass Agnatha
lamprey
- lambere = to lick
- petro = stone
- Notochord, has arcualia (cartilage), no bone, no scales
- lateral line present
- Some parasitic, others do not feed adults
- Devonian to present
Class Petromyzoniformes
phylum
subphylum
superclass
meaning
what do they have and not have
feed
time
69
Phylum Chordata, ~Subphylum Vertebrata
Superclass Agnatha
The Conodonts
(Gr. cono = cone, odont = teeth)
teeth (conodonts) - calcium phosphate (not bone)
Post-anal tail & myomeres, no gill slits (expect in one specimen), maybe a nerve cord, maybe a notochord
Fossils in Cambrian - Triassic
Class Conodonta
phylum
subphylum
superclass
70
Phylum Chordata, Subphylum Vertebrata
Superclass Agnatha
shell skins
Gr. ostracon = shell; derma = skin)
Paraphyletic group, of jawless fish covered with large bony plates
notochord with vertebral neural
arches only
Paired fins in one type only
Fossils in Cambrian - Devonian
Ostracoderms
phylum
subphylum
superclass
group of..?
what do they have
one type hass
time
71
jaws
what does gnathans mean
72
Phylum Chordata, Subphylum Vertebrata
Superclass Gnathostomata
Class Placodermi (placo = plate/flat stone)
Bony plates
“Invented” jaws
Paired fins, notochord with vertebral neural and hemal arches (no centrum)
Fossils in Silurian – Permian
Class Placodermi
phylum
subphylum
superclass
what do they have
what do they not have
time
73
Phylum Chordata, Subphylum Vertebrata
Superclass Gnathostomata
vertebrae, lack bone – has cartilage (2º loss), placoid scales
Subclass Elasmobranchii
– (Gr. Elasmos = metal beaten out; branchia = gill)
- skates, rays, sharks
Subclass Holocephalii
– (Gr. Holo = complete; cephalic = head)
- chimeras
Devonian - present
Class Chondrichthyes
phylum
subphylum
supere class
what do they have
two subclasses
what do they consist of
time
74
small fins on tail
swim by creating a wave and starts at head then ripples down rest of body
- oviparous (egg laying)
describe a skate
fins
swim
offspring
75
venomous barb or spines
- swims by moving finds up and down like a bird
- ovoviviparous - egg hatch within the body
describe a ray
what do they have
swim
offspring
76
Phylum Chordata, Subphylum Vertebrata
Superclass Gnathostomata
(acanthos = spine)
Sister group to Osteichthyes
Distinctive spine in fins
Cartilaginous
Have scales more like those of bony fish
Fossils in Silurian - Permian
Class Acanthodi
sister group
traits (3)
time
77
Look like sharks - have cartilaginous endoskeleton
However, have scales more like boney fish (specifically rhomboid shaped ganoid scales similar to gar and Amia) and fins have a boney base with a dentine spine
are acanthodian sharks?
78
Phylum Chordata, Subphylum Vertebrata
Superclass Gnathostomata
the bony fish (Gr. osteon = bone)
Bony skeleton primitive
Two subclass:
– *Subclass Actinopterygii (ray-finned fishes)
– *Subclass Sarcopterygii (lobe/fleshy-finned)
Devonian – present
Class Osteichthyes
skeleton
subclasses
time
79
Class Osteichthyes
Lungs or swim bladder
Lepidotrichia in fins
Scales
ex: amia, polypterus (diverse group)
Subclass Actinopterygii (ray-finned fishes)
what do they have
examples
80
Class Osteichthyes
(sarc = flesh; pterygi = fin)
a.k.a Choanichthyes – (choan = funnel/internal nares)
Superorder Coelacanthiformes or Actinistia or Crossopterygii (krosso = fringe) = the coelocanths (mid-Devonian-present)
* *Superorder Dipnomorpha (early-Devonian-present) – Order Dipnoi (di = two; pneo = breath, air or lungs) having both gills & lungs
* *Superorder Rhipidistia (mid-Devonian) – all extinct, most closely related to coelacanths, ancestral to tetrapods
Subclass Sarcopterygii
81
multiple dorsal and ventral fins
Sarcopterygians structure
82
No internal nares (lost), Thought to be extinct, Rediscovered, 1938, found off the east coast of South Africa, mid-Devonian-present
Superorder Coelacanthiformes or Actinistia or Crossopterygii (krosso = fringe) = the coelacanths
83
(di = two; pneo = breath, air or lungs) – gills & lungs)
Three extant genera
Devonian - present
in australia in turbid water, breathing air
in africa - estivate through dry season by burrowing in mud, slows its metabolism, less toxic urea (waste)
South America - found in swamps and slow moving waters, obligate air breather, burrows in mud, makes a chamber, leaving holes to the surface for air
Superorder Dipnomorpha, Order Dipnoi
84
Devonta era - tropical with seasonal droughts
ways to survive - move from dry areas to wetter areas
Rhipidistians
how did they survive
85
Phylum Chordata, Subphylum Vertebrata
Superclass Gnathostomata
Class Osteichthyes – the bony fish (Gr. osteon = bone)
Subclass Sarcopterygii
Paraphyletic group; all extinct, gave rise to tetrapods
* Internal nares, loss of median fin
* Fin elements correspond begin to resemble tetrapod limb bones (“pre-adaptation”)
* ex: Tiktaalik - shoulder girdle separate from skull
* Fossils in the Devonian – Early Permian
Superorder Rhipidistia
three traits
example
time
86
Eusthenopteron, Pandericthys, and Tiktaalik
example of Rhipidistians
87
NOTE SHOULDER GIRDLE! Looks very amphibian-like
what's special about Tiktaalik
88
Fish with better “on land” crawling skills are
selected
* Traits associated with being better able to walk
on land:
– Loss of median fins
– Legs (from lobe fins)
– Scales reduced (greater body movement)
– Pelvic girdle attached to vertebral column (supports
body out of water)
– These traits are found in Subclass
Labyrinthodontia
Labyrinthodonts
special traits (4)
subclass
89
Phylum Chordata, Subphylum Vertebrata
Superclass Gnathostomata, Class Amphibian*
(labyrinth = maze, odont = teet)
All extinct, gave rise to amniotes (cotylossauria), our ancestors
* No median fins, scales reduced, have legs – likely crawled by lateral undulations
* Pelvic girdle attached to vertebral column
* Late Devonian
* Maze like pattern in teeth
* Sister group to Amphibia
Subclass Labyrinthodontia
class
alive?
gave rise to
whose ancestor
five traits
time
sister group
90
Acanthostega, Icthyostega, and Seymouria
examples of Labyrinthodonts
91
NOTE Pectoral (not attached to skull) and pelvic girdles (attached to vertebral column)
what is special about Seymoria
92
Vertebra divided in to multiple parts – separate pleurocentrum and intercentrum.
* Related or ancestral to modern Amphibians.
* Early Carboniferous (Mississippian) to early Cretaceous
Other Labyrinthodonts: Order* Temnospondyls
spine
relations
time
93
Related or ancestral to all or some modern
Amphibians
* Loss of labyrinthodont teeth – 2o loss or not?
* Solid spool shaped vertebra with neural spine, two centrum
* Early Carboniferous to late Permian
* *More recently moved out of the Labyrinthodont group*
class amphibia, subclass lepospondyls
loss
related acestral to who
vertebra
time
move from
94
Amphibian
Modern day Amphibians + Labyrinthodonts are all in Class ___
95
labyrinthodonts
Safe to say that modern anamniotes and amniotes come from ___
96
diphyletic
Amphibians may be a ___ group
97
derived from two lines of evolutionary decent
diphyletic
98
temnospondyls alone rather than both temnospondyls and lepospondyls OR lepospondyls alone
More recently the field is leaning toward the idea of modern amphibians being descended from
99
Cotylosaurs
Labyrinthodonts Gave Rise to
100
Loose term used to refer generally to basal amniotes
Cotylosaurs
