Week 2 - Fossil Preservation Flashcards
What is the definition of taxonomy?
Ordered classification of organisms into categories based on shared characteristics
Examples of shared characteristics include morphology and DNA.
What is the purpose of taxonomy?
Reflects evolutionary pathways and shows relationships between organisms using a hierarchical structure
Hierarchical structure includes Domain, Kingdom, Phylum, Class, Order, Family, Genus, and Species.
What are the main components of the hierarchy in taxonomy?
Domain, Kingdom, Phylum, Class, Order, Family, Genus, Species
This structure is built upon Carl Linnaeus’s taxonomic system and Charles Darwin’s theory of evolution.
What do phylogenetic trees illustrate?
Relationships and divergence points in evolution
Branch points show when species diverged from a common ancestor.
What factors influence fossil preservation?
Environment, sedimentation, and the organism’s composition
Hard parts like shells and bones are more likely to be preserved.
What is the relationship between sedimentation rate and fossil preservation?
Faster sedimentation rates bury organisms quickly, aiding preservation
This helps in protecting fossils from decay.
What oxygen level is favorable for fossil preservation?
Low oxygen (anoxia)
It reduces decay and scavenger activity.
What are common materials found in the hard parts of fossils?
Calcite, aragonite, silica, calcium phosphate
These materials affect the preservation quality.
What process involves the alteration of minerals in fossils over time?
Diagenesis
An example includes aragonite transforming into calcite.
What conditions are ideal for fossil preservation?
Fine sediment and anoxic environments
Fossils in these conditions retain more detail and original structures.
What phylum do ammonites belong to?
Mollusca
Ammonites are classified under the class Cephalopoda.
What are the features of ammonites?
Phragmacone, body chamber, sutures
The phragmacone provides buoyancy.
What are the evolutionary forms of ammonites?
Goniatitic, Ceratitic, Ammonitic
These forms represent different stages in ammonite evolution.
What is the ecological role of ammonites?
Marine organisms with buoyant shells, occupying diverse habitats
They played significant roles in marine ecosystems.
What phylum do belemnites belong to?
Mollusca
Belemnites are classified under the class Cephalopoda.
What is a key feature of belemnites?
Rostrum
It is a solid internal structure made of radial calcite, commonly preserved.
How do belemnites differ from ammonites in terms of shell structure?
Belemnites have no external shell, only a rostrum
Ammonites have a chambered shell with complex sutures.
What lifestyle did belemnites lead?
Nektonic, actively swimming
Likely predators, moving freely in marine environments.
True or False: Ammonites and belemnites lived in the same era.
False
Ammonites lived from the Devonian to the Cretaceous, while belemnites were present in the Mesozoic (Triassic to Cretaceous).
Fill in the blank: Ammonites evolved from ______ to ______.
Goniatitic to Ammonitic
This represents the evolutionary transition in ammonite forms.
What is the primary external feature of ammonoids?
Ammonoids have coiled, chambered shells with complex suture patterns that connect the chambers.
What are the internal features of ammonoids?
Internally, ammonoids have chambers (or camerae) connected by a siphuncle, used to regulate buoyancy.
What distinguishes the suture patterns in ammonoids?
Their suture patterns range from simple (goniatitic) to highly complex (ammonitic), which help in species identification.
What is the primary external feature of belemnites?
Belemnites have a bullet-shaped calcite guard (rostrum) as their most recognizable external feature.
What internal features are present in belemnites?
Internally, belemnites have a phragmocone (a chambered shell) and a proostracum (a thin, blade-like structure).
How did ammonoids contribute to their environment’s ecosystem?
Ammonoids were active marine predators and prey for larger marine animals, playing a vital role in the food chain.
How are ammonoids used as zone fossils?
Ammonoids evolved rapidly and had widespread geographic distribution, making them excellent indicators for dating and correlating rock layers in geologic
What evolutionary trait of ammonoids makes them useful for stratigraphy?
The rapid evolution and distinct changes in shell morphology and suture patterns over time make ammonoids highly valuable for precise biostratigraphy.
What role did the rostrum of belemnites play?
The rostrum provided counterbalance for buoyancy and served as structural support for the soft body.
What evolutionary advantage did ammonoids gain from their complex suture patterns?
Complex suture patterns increased shell strength, allowing ammonoids to withstand greater depths and pressures in the marine environment.
