Verts Lecture Exam 1

Ectoderm

Outer germ layer, integument

Endoderm

Inner germ layer, lines the gut

Mesoderm

Middle germ layer, forms muscle and organs

Metazoa

Multicellular animals

Porifera

No germ layers, organs, or true tissues; intracellular digestion (sponges)

Eumetazoa

Germ layers, true tissues, and organs present, mouth and digestive system present (all other animals but sponges)

Bilateria

Group of Eumetazoa that have bilateral symmetry and 3 germ layers.

Nephrozoa

Group of Bilateria that have a coelom (fluid around the gut) present

Protostomia

Animals that develop the mouth first (from blastopore)

Deuterostomia

Animals that develop the anus first (from blastopore)

Ambulacraria

Group that contains the echinoderms and hemichordates

Echinodermata

Radially symmetrical invertebrates (under classification of ambulacraria and deuterostomia) eg. Starfish

Hemichordata

Bilaterally symmetrical invertebrates (under classification of ambulacraria and deuterostomia) Eg. Acorn worms

Chordata

Phylum that describes vertebrates (bilateral symmetry)

Urochordata

Subphylum of chordata, describes tunicates

~2000

How many described species of Urochordates are there?

Urochordates

1. Body with two openings: 1) Branchial siphon; draws water into basket like pharynx leading into the atrium. 2) Atrial siphon; exit for waste and water
2. Simple circulatory and digestive systems.
3. Tail and notochord present in larvae (lost when tunicates become immobile)

Appendicularian tunicates

Tunicates that retain larval characteristics in their adult stage

Cephalochordata

Subphylum of Chordata, describes lancelets

~22

How many described species of cephalochordates are there?

Cephalochordates

1. Body with three openings: 1) mouth 2) atriopore (exit of atrium) water exits 3) anus; waste exits.
2. Well developed circulatory and digestive system.
3. Notochord is well developed and extended through entire length of body ( present in adult stage)
4. Myomeres (blocks of muscle) along entire length of body.

Vertebrata

Subphylum of Chordata, describes "typical" vertebrates; chordates with craniums

Olfactores

Name for a hypothetical group describing urochordata as the sister group to Vertebrata.
Cephalochordata (Urochordata,Vertebrata)

Polytomy

An area of a phylogenetic tree that does not bifurcate.

Notochord

The most characteristic trait of chordates.

1. Notocord 2. Single, dorsal hollow nerve cord 3. Pharyngeal pouches and slits 4. postanal tail 5. segmented body, including myomeres 6. endostyle 7. ventral heart and closed circulatory system

Traits of chordates

-No Song Peter Piper Sings Ends Valiantly-

Endostyle

Thyroid gland/filter feeding groove. Trait of chordates

Pharyngeal pouches and slits

A trait of all chordates at some stage that facilitates filter feeding

Telencephalon

Aka cerebral membrane, largest part of the brain

Myomeres

Blocks of muscle all chordates have at some stage.

Adenohypophysis

anterior pituitary gland

Coelom

Fluid filled space that surrounds the gut

Neural crest

4th germ layer- contributes to formation of gill arch skeleton and paired sense organs

Hox genes/cluster

Groups of genes; key genes that dictate patterns of development in the body.

Cambrian Period

Where we can find the earliest fossil chordates

Pikaia

First known chordate

Haikouella

1st known creature with a tripartite brain and pharyngeal rods developed from a neural crest.

Cristazoa

Name of grouping for chordates possessing a neural crest

Cyclostomata

Jawless fishes, hagfish and lampreys

Gnathostomata

Jawed vertebrates
1. 2 pairs of appendages
2. 3 semi-circular canals in inner ear

Agnatha and Gnathostomata

Subphylum Vertebrata divides into these groups

Chondrichthyes and Osteichthyes

Eugnathostomes, a group characterized by mineralized teeth, contains:

Vertebrate Synapomorphies

1. Well developed eyes
2. Pineal eye "third eye"
3. Lateral line system
4. Capacity for electroreception
5. Two semi-circular canals in inner ear.

Chronogram

Phylogenetic tree in which the branch lengths are proportional to time

Myllokunmingia and Haikouichthys

Jawless vertebrates that represent the Cambrian Period

Hagfish and Lampreys

Which group(s) are currently accepted as the sister group of Gnathostomata

Cyclostomata

1. Lingual cartilage
2. Keratinous teeth
3. Cartilaginous gill supports

Hagfish

Most basal vertebrate, well developed olfactory senses, SINGLE MEDIAN NOSTRIL aka nasohypophyseal pore that connects to the pharynx

Lampreys

No jaws, oral sucking disk with keratinous teeth, 7 external gill openings

Chestnut lamprey, Southern brook lamprey

Lampreys found in Texas

Balaenoptera musculus

Scientific name for the blue whale
-Largest species of vertebrate known to inhabit the earth ever
-Up to 33m in length

Paedocypris progenetica

-World's smallest living species of vertebrate
-Sexually mature at 7.9mm

Extant

Term for currently living species

71,000

There are approximately __________ species of extant vertebrates

Binomial Nomenclature

A system for giving each organism a two-word scientific name that consists of the genus name followed by the species name

Linnaean Classification System

-Employs binomial nomenclature to designate species and arrange them into hierarchical categories
-Dates back to 1758
-Mnemonic: "Dear Kevin Please Come Over For Gay Sex"

Reptilia

Discovery of __________
-2005: 8,780 species
-2015: 10,500 species

Amphibia

Discovery of __________
-1994: 4,650 species
-2003: 5,723 species
-2017: 7,726 species

Carl Von Linne

Modern taxonomy is attributed to __________

Carolus Linnaeus

Linne gave himself a nomenclature name of ____________

Willi Hennig

The German entomologist who invented Phylogenetic systematics

Plesiomorphy

A trait inherited unchanged from an ancestor. 2+ taxon sharing this trait is called a symplesiomorphy.

Apomorphy

A derived trait different from the ancestral condition.

Synapomorphy

Apomorphic characters displayed by 2+ taxon, used to determine phylogenetic relationships.

1. Dermal jaw bones 2. Endochondral bone 3. Gas filled bladder 4. fin rays (lepidotrichia)

4 Traits of Osteicthyes

Don’t Eat Green Lemons

Otophysi

A group characterized by the presence of a Webarian apparatus connecting the cranium and swim bladder to improve hearing.

Endoskeleton

Skeleton derived from ossified cartilage

Exoskeleton

A skeleton derived from the dermis that contains dentin, enamelin, and dermal bone. It also contains hydroxyapatite, a mineral unique to vertebrates.

Teleosts

1. Homocercal caudal fin (no lift)
2. specialized jaw not connected posteriorly (suction feeding)
3. Light and flexible elasmoid (cycloid and ctenoid) scales

lamellae

Gill filaments are present in vertebrates to facilitate gas exchange. Oxygen flows unidirectionally opposite from the blood in countercurrent exchange. A 1-cell thick epithelium separates water and blood.

Ostracoderms

An extinct group notable for having the first paired pectoral fins, from the mid-Devonian

Spiracle

Opening between the mandibular arch and hyoid arch that indicates the 2nd gill arch might have had respiratory function.

gill arches

mandibular arch - forms jaw
hyoid arch - forms jaw support
branchial arches - arch 3-7, form gill arches

Autostylic

The upper jaw connects to the cranium anteriorly, not posteriorly

Amphistylic

The upper jaw connects to the cranium anteriorly, is free posteriorly, and is braced by the hyoid arch

Hyostylic

the upper jaw is not connected directly to the cranium, but attached via hyomandibular cartilage

Holostylic

The upper jaw is fused to the cranium and immobile

Homodont

One one type of tooth

Heterodont

Multiple types of teeth

polyphyodont

Teeth are constantly being replaced. Replacement teeth can be arranged in a conveyor belt or tooth whorl.

Chondrichthyes

1. pelvic claspers
2. cartilaginous endoskeleton with tesserae
3. Placoid scales

Holocephali and Elasmobranchii

Subclasses of Chondrichthyes

Ampullae of Lorenzini

Organ in the skin of the rostrum that facilitates electrosensitivity.

Matrotrophy

A form of viviparity where the young’s egg sac fuses to the mother to provide additional nourishment.

They are long-lived and reproduce infrequently

Reasons why sharks are vulnerable to exploitation

basal Actinopterygians

Polypteriformes (bichers), Acipenseriformes (sturgeon), Lepisoteiformes (gar), and Amiiformes (bowfin)

Devonian period

The period where fossils of all major fish lineages are represented in marine and freshwater deposits. (Age of fishes)

Sarcopterygii and Actinopterygii

Classes of Ostiechthyes

Sarcopterygii

A class that 1st appeared in the Silurian/Devonian transition, characterized by paired fins attached via a single basal element

Actinistia

An extant group in Sarcopterygii with:
1. 2 dorsal fins
2. symmetrical diphycercal caudal fins
3. Intracranial joint

Dipnoi

An extant group in Sarcopterygii with:
1. A diphycercal caudal fin
2. upper jaw fused with cranium
3. can estivate to hibernate in dry summers

1. Pectoral girdle separate from the skull 2. limbs with carpels, tarsals, and phalanges 3. sacral region - where the pelvic girdle attaches to the spine 4. Zygapophyses - interlocking vertebra

The largest group in Sarcopterygii.
characteristics of Tetrapods:
“Please Leave Sacred Zones”

Ichthyostega

Contender for 1st terrestrial tetrapod found in the late Devonian

Acanthostega

First true tetrapod with all 4 tetrapod characteristics found in the late Devonian

Tiktaalik

The “missing link” between tetrapods and tetrapod-like fishes

Coelacanthiformes

An ancient group of lobe-finned fishes with only 2 extant members (Actinistia and Sarcopterygii)

1. 2 dorsal fins
2. diphycercal caudal fin
3. rostral organ - senses electrical currents
4. intracranial joint

Latimeriidae

The Family Coelacanths belong to

Ceratodontiformes

The order that lungfish belong to, under Dipnoi

Neocerodontidae

Family of Australian lungfish

Lepidosirenidae

Family of South American lungfish