Humanity on The Record Answers

Comprehension Questions

1. What are Homo sapiens
  1. the use of technology to detect radioactive elements
  2. a fossil record that covers two centuries
  3. our species, the human race
  4. a species that has gone extinct

2. What sequence of events does this passage describe? 
  1. This passage describes the daily routine of Homo neanderthalensis and Homo heidelbergensis.
  2. This passage describes the appearance and disappearance of different species related to humans.
  3. This passage describes the steps that paleontologists took to find pieces of human skull and bone in Kenya.
  4. This passage describes the assembly of a fossil record that dates Homo sapiens to about 200,000 years ago.

3. Fossils can provide information about the history of humankind.What evidence from the passage supports this statement? 
  1. “Assembling a ‘fossil record’ over the course of two centuries, scientists have amassed enough evidence to date the earliest known appearance of Homo sapiens to about 200,000 years ago.”
  2. “At the moment, our human race carries the torch for millions of years of evolution—among species, across continents, and through the ages.”
  3. “Some scientists argue that Neanderthals may have bred with early populations of modern humans, changing the record of their extinction to one of possible assimilation.”
  4. “The simultaneous existence of Homo erectus and Homo heidelbergensisHomo floresiensis and Homo neanderthalensis covers a period when the human races developed much larger brains and began to form the basis for modern civilization.”

4. Imagine that a group of scientists has just dug up a fossil. What would probably give them the most information about the age of that fossil? 
  1. the fossil itself
  2. the earth around the fossil
  3. the air around the fossil
  4. the water around the fossil

5. What is this passage mostly about? 
  1. the appearance and behavior of Homo heidelbergensis
  2. the question of whether humans evolved from apes
  3. the use of radiometric dating to determine the age of fossils
  4. the development and fossils of prehistoric humans

6. Read the following sentence: “If people find a fossil between two layers of dirt, and they know how old those layers of dirt are, they can then say the fossil was part of a living creature between those dates.”What does the word fossil mean in the sentence above? 
  1. the slow development of a species over time
  2. part of a living thing that has died and remained in the ground for a long time
  3. a method that scientists use to determine the age of bones they find in the ground
  4. an early human-like species that walked upright and probably used stone tools

7. Choose the answer that best completes the sentence below.There are several methods for dating fossils, ______ stratigraphy and radiometric dating. 
  1. therefore
  2. earlier
  3. also
  4. including

8. What did scientists discover on a 2012 fossil excavation in Kenya? 

Scientists discovered pieces of human skull and bone that are approximately 2 million years old.

9. What did this discovery tell scientists? 

This discovery told scientists that humankind is merely one of a number of human-like species, each with its own lifespan.

10. Explain how fossils can teach scientists about the development of humans. Support your answer with an example from the passage. 

Answers may vary, as long as they are supported by the passage. For instance, students may respond that fossils can tell scientists when humans came into being, what related species preceded them, and what related species coexisted with them. Students may cite the discovery of the 2 million-year-old human bone fragments in Kenya as an example of fossils that provide information about human development.

 

Humanity on The Record Reading Comprehension

human skulls damage

 

 

In the summer of 2012, paleontologists working on a fossil excavation in Kenya announced that the human race, as we know it, was never alone.

Scientists unveiled pieces of skull and bone that are approximately 2 million years old. Their discovery confirmed what earlier fossil findings had introduced as a possible piece of the human origin story: that humankind is merely one of a number of human-like species, each with its own lifespan. Every other species has been long extinct, making Homo sapiens, our species, the sole surviving member of the extended human family. Indeed, these findings have confirmed that the family was bigger than anyone had previously imagined.

In conversations about prehistoric evolution, whether humans evolved from apes, is a common but misleading question. Evolution, at its core, is a process that spawns a diversity of species. Some are quite similar and some are quite different. Some strains of evolution take place over millions of years, while other strains (for example, microorganisms that pass through multiple generations in the span of a day) take place over a number of months, even weeks. To track the evolution of various organisms over time is to reveal the natural world’s knack for never putting all of its bones in one basket, so to speak.

Dating Prehistoric Man: Not as Awkward as It Sounds

A more revealing question, then, is scientists’ inquiry into multiple branches of the Homo genus. Assembling a “fossil record” over the course of two centuries, scientists have amassed enough evidence to date the earliest known appearance of Homo sapiens to about 200,000 years ago. Their research has also proven that a number of human-like species preceded and accompanied Homo sapiens on the prehistoric timeline.

The creation and preservation of an accurate fossil record is no easy task. Bones dug up from the ground don’t often offer much information about their own age, so paleontologists have developed several methods to analyze the earth surrounding those bones instead. By inspecting the proximity of a fossil, one can figure out approximately (sometimes precisely) when the fossil itself was actually a living organism.

Radiometric dating—the use of technology to detect radioactive elements to identify the age of whatever those elements are in—is a precise but limited technique for determining the age of a fossil. The precision of radiometric dating comes from the fact that radioactive elements have clear, well-documented decay times (or how long it takes for traces of an element to disintegrate). Using this technique, scientists can narrow down the age of a fossil, even one that’s over 50 million years old, to a very close estimate. Unfortunately, radiometric dating only works when radioactive elements were present in the first place.

The alternative method of dating fossils is stratigraphy. Based in the geographic study of layers of sediment that have stacked on top of each other for ages, stratigraphy includes a host of techniques for analyzing these various layers to determine the age of objects found wedged within them.

Simply put: If people find a fossil between two layers of dirt, and they know how old those layers of dirt are, they can then say the fossil was part of a living creature between those dates.

Stratigraphy can be difficult to execute in the study of fossils, since dirt doesn’t always stack up in neatly preserved layers. There are often interruptions in the layers or portions of sediment that ended up being mixed together or eroded. Furthermore, the precision of this technique is said to be relative. Every estimate based on stratigraphic analysis depends on a comparison between other samples and other estimates.

Yet, by reviewing each other’s evidence and sharing their findings, researchers are able to make reasonable confirmations of the global fossil record. Radiometric dating and stratigraphic dating are used to establish prehistoric records of fossils. Those records are then used to build a logical timeline for the evolution of many species. When new fossils are dug up, a fossil record spanning the ages is there to help scientists figure out where their new discoveries fit into the stories of the earth.

To Err Is Human; to Evolve Is Much More

One of the most fascinating stories, of course, is the prehistory of the human race.

The National Museum of Natural History puts it eloquently: “While people used to think that there was a single line of human species, with one evolving after the other in an inevitable march towards modern humans, we now know this is not the case. Fossil discoveries show that the human family tree has many more branches and deeper roots than we knew about even a couple of decades ago.”

Presenting an interactive display of humanity’s prehistory, the museum identifies over 15 different species related to humankind. The fossil record reaches back over 6 million years, marking the earliest known appearance of a primate species that walked upright. Two million years later, the record proves the existence of Australopithecus Anamensis, a bipedal species that was equally adept at walking upright and climbing trees.

Homo habilis, whose fossils date back 2 million years ago, was the earliest known species of the Homo genus. The age of Homo habilis closely follows the first known appearance of stone tools. It also coincides with the existence of at least three other human-like species, ape-like creatures that also walked upright. The stone tools discovered from these years were likely used by all of the species, following evolutionary paths that were similar but far from identical.

Even Homo sapiens, the species encompassing every human being on the planet right now, were accompanied by similar species. To be exact, at least four other human species have been added to the fossil record for the past million years. The simultaneous existence of Homo erectus and Homo heidelbergensisHomo floresiensis and Homo neanderthalensis covers a period when the human races developed much larger brains and began to form the basis for modern civilization.

One by one, the other races have gone extinct. The hypothesized reasons range from an inability to adapt to climate change to murder at the hands of more advanced humans. Disease, physical disadvantages, and natural disaster have been discussed as possible causes. Some scientists argue that Neanderthals may have bred with early populations of modern humans, changing the record of their extinction to one of possible assimilation.

Thus, precise causes for the ascendency of Homo sapiens have yet to be proven. The fact that fossils represent less than 5% of all known living species in the history of the world makes it very difficult for even the brightest paleontologists to gather enough evidence to answer all the questions they have about the origins of man.

What the world has gained through their work, though, is less a story of primates transforming into humans than it is the story of humanity’s many extinguished flames. At the moment, our human race carries the torch for millions of years of evolution—among species, across continents, and through the ages.

 

Comprehension Questions

1. What are Homo sapiens
  1. the use of technology to detect radioactive elements
  2. a fossil record that covers two centuries
  3. our species, the human race
  4. a species that has gone extinct

2. What sequence of events does this passage describe? 
  1. This passage describes the daily routine of Homo neanderthalensis and Homo heidelbergensis.
  2. This passage describes the appearance and disappearance of different species related to humans.
  3. This passage describes the steps that paleontologists took to find pieces of human skull and bone in Kenya.
  4. This passage describes the assembly of a fossil record that dates Homo sapiens to about 200,000 years ago.

3. Fossils can provide information about the history of humankind.What evidence from the passage supports this statement? 

  1. “Assembling a ‘fossil record’ over the course of two centuries, scientists have amassed enough evidence to date the earliest known appearance of Homo sapiens to about 200,000 years ago.”
  2. “At the moment, our human race carries the torch for millions of years of evolution—among species, across continents, and through the ages.”
  3. “Some scientists argue that Neanderthals may have bred with early populations of modern humans, changing the record of their extinction to one of possible assimilation.”
  4. “The simultaneous existence of Homo erectus and Homo heidelbergensisHomo floresiensis and Homo neanderthalensis covers a period when the human races developed much larger brains and began to form the basis for modern civilization.”

4. Imagine that a group of scientists has just dug up a fossil. What would probably give them the most information about the age of that fossil? 
  1. the fossil itself
  2. the earth around the fossil
  3. the air around the fossil
  4. the water around the fossil

5. What is this passage mostly about? 
  1. the appearance and behavior of Homo heidelbergensis
  2. the question of whether humans evolved from apes
  3. the use of radiometric dating to determine the age of fossils
  4. the development and fossils of prehistoric humans

6. Read the following sentence: “If people find a fossil between two layers of dirt, and they know how old those layers of dirt are, they can then say the fossil was part of a living creature between those dates.”What does the word fossil mean in the sentence above? 

  1. the slow development of a species over time
  2. part of a living thing that has died and remained in the ground for a long time
  3. a method that scientists use to determine the age of bones they find in the ground
  4. an early human-like species that walked upright and probably used stone tools

7. Choose the answer that best completes the sentence below.There are several methods for dating fossils, ______ stratigraphy and radiometric dating. 

  1. therefore
  2. earlier
  3. also
  4. including

8. What did scientists discover on a 2012 fossil excavation in Kenya? 

9. What did this discovery tell scientists? 

10. Explain how fossils can teach scientists about the development of humans. Support your answer with an example from the passage. 

 

 

 

Reading for Fun: Non-Fiction

The Virtues of Difficult Fiction | The Nation

Hello all, we will use the same activities from last week. Remember, non-fiction reading can be anything that is real/true. For example, newspapers, “how-to” books/manuals, magazines (about real things), encyclopedia etc…   So… go ahead and choose a non-fiction book and pick one (or more) of the fun activities below.

Enjoy! And tell us which activity you chose and why!

Screenshot 2020-05-08 at 14.51.02

 

The Fossil Finessers

This text is provided courtesy of the American Museum of Natural History.

In the course of more than a century of fossil collecting, Museum paleontologists have unearthed fossils from every corner of the globe. But there are some sites so fruitful in fossils that they are visited again and again by the Museum’s fossil hunters, with each generation turning up new and unexpected finds.

The entrance to Ghost Ranch, which the Museum's paleontologists have been excavating for decades.

AMNH / Division of Paleontology Archives

The entrance to Ghost Ranch, which the Museum’s paleontologists have been excavating for decades.

One of those sites is New Mexico’s Ghost Ranch, home to four quarries that paleontologists from the Museum have excavated for decades. The remains of animals from the Triassic era, including dinosaurs, reptiles, and fishes, have all been discovered here, often preserved in exquisite condition. “These animals lived in a very different environment,” says Sterling Nesbitt, a research associate at the Museum who has spent 10 field seasons at the site. “About 212 to 200 million years ago it was marshy. There were big rivers going through this part of the United States. Think Mississippi Delta.”

Paleontology began in earnest at Ghost Ranch in 1928, when the fossilized remains of crocodile-like reptiles including phytosaurs and aetosaurs were discovered by researchers from the University of California. The Museum’s work at Ghost Ranch began two decades later, in 1947, when curator Edwin H. Colbert and his team came upon a veritable graveyard of Coelophysis bauri in what is now called Whitaker Quarry. These early dinosaurs were small, fast, bipedal predators that likely chased down prey while looking much like a tiny T. rex.

telegram

AMNH / Research Library

An excited telegram from the Museum’s team in the field at Ghost Ranch to the Paleontology Department on June 30, 1947.

fossil hunters

AMNH / Division of Paleontology Archives

Fossil hunters working in 1947 at the site that would later be called Whitaker Quarry, after Museum paleontologist George Whitaker.

The specimens Colbert found were remarkably well-preserved, complete, and in many cases articulated. The fossil discovery was also one of the most notable in the history of the state, and led to Coelophysis bauri being named the official state fossil of New Mexico in 1981.

But just discovering a specimen doesn’t make it useful to science. Despite enduring for millions of years, fossils of even the most awesome ancient animal can be fragile things. They must be excavated and prepared for study with painstaking care.

Preparing a fossil begins before the specimen even arrives in the Museum. In the field, a fossil find deemed worthy of bringing back for study is first encased in plaster, specifically plaster bandages—just like the ones that go into making a cast for a broken limb. They serve the same purpose, immobilizing and protecting a specimen for shipment back to the Museum from far-flung regions like Ghost Ranch, the Gobi Desert, or the Museum’s other dig sites around the world.

shellac

AMNH / Division of Paleontology Archives

Shellac is applied to an exposed skull.

Carl Sorensen George Whitaker

AMNH / Division of Paleontology Archives

Museum paleontologists Carl Sorensen and George Whitaker drip strips of burlap sacks in plaster of Paris and apply to the specimen block to create a “carrying jacket.”

GW plaster block

AMNH / Division of Paleontology Archives

George Whitaker and associate undercut a plastered block so that it can be removed from the quarry.

tripod

AMNH / Division of Paleontology Archives

To pull up the heavy blocks from the quarry, the Museum team constructed a tripod.

plaster specimen

AMNH / Division of Paleontology Archives

a plastered specimen block

1500 pounds

AMNH / Division of Paleontology Archives

Each block weighs between 1,500 and 6,000 pounds. Here, the specimens are loaded onto a truck, which drove from New Mexico to New York.

“Plaster bandages are a good choice because they dry faster than regular plaster,” says Senior Principal Preparator Ana Balcarcel. “They also use less water, which is important when you’re in the field, where water can be at a premium.”

Once protected in plaster, these specimens are moved from the dig site and annotated with a series of field notes. These record for posterity where, when, and by whom a fossil was excavated, indicate estimates of how many fossils are in a given block, and offer preliminary identification of the remains. Once these notes are made, the specimen is placed in a crate and shipped to the Museum.

For some fossils, that’s where the story takes a very long pause. Preparing a fossil takes a very long time, and the work has to be done by hand with the utmost care. That means that, in a world-class collection like the one housed in the Museum’s Division of Paleontology, there are more fossils in the collection than time or experts to prepare them.

Preparators’ schedules are also determined by current research projects, and newly excavated items can take precedence. But maintaining all these crated fossils, says Ruth O’Leary, director of collections, archives, and preparation in the Division of Paleontology, is key to maintaining a healthy collection.

“A minority of the fossils we collect remain in crates for a variety of reasons. They are packed well and protected in the crates and don’t get moved around much. They take up less room than specimens in cabinets, which can be important when storage is at a premium. And we know what’s in the crates so they are accessible to researchers when they become a priority for study,” O’Leary says.

When a request to study a fossil lands at the top of a preparator’s to-do list, whether the specimen is fresh from the field or swaddled in shredded newspaper from the 1930s, the process is largely the same. It begins with a round of research, since preparators have to be anatomy experts to navigate a fragile fossilized specimen.

Before any work is done to remove the fossil, they hit the published literature to bone up on the specimen they’re about to begin extracting, or similar related creatures if an identification hasn’t been made. That’s when the real work of removing fossils from rock starts.

“Our basic function is to remove the specimen from the matrix, the stone it’s enclosed in, or if it’s too unstable for that, to expose the specimen within the rock,” says Balcarcel. “We want to salvage everything.”

Tools of the trade range from needle-like chisels to tiny jackhammers. For stable specimens, much of the extraction work is done using handheld pneumatic jackhammers capable of pulverizing rock. Powered by jets of pressurized air, these machines chip away at the stone bit by bit, revealing the fossil.

For more delicate work on unstable fossils, or finishing touches made closer to the bone, preparators use needles, brushes, and sharp sculpting tools to remove the final vestiges of rock from a fossil.

While today this work is done with the assistance of high-powered microscopes, the process of finishing a fossil in this way would look very familiar to a preparator from a century ago—and the tempo hasn’t changed a bit, either. Some things, it turns out, you just can’t rush.

fossil mold

AMNH / R. Mickens

Museum preparator Ana Balcarcel with a fossil mold.

Once a fossil is extracted, or as exposed as it can safely be, preparators often back up their hard work, making a silicon mold that can be used to create casts of the fossil. These casts, most often made from a polyester resin, are key to paleontological research. In addition to serving as a just-in-case reminder of the fossil’s exact dimensions and features, they also make it easier to study the specimen without handling it, reducing the likelihood that it will be damaged. Casts can also be made and sent to researchers around the world while the original stays safe in the collection. They can even improve researchers’ understanding of the real fossil.

“The grey coloration of the cast helps detailed textures show up and prevents you from being distracted by multiple colors that could be found in the fossil,” Balcarcel says. “Sometimes, a cast can be more informative than the original.”

And while most of the work is still done with traditional tools, new technology is slowly beginning to change the field. Computed tomography (CT) scans of fossils, for instance, can provide scads of information about what’s contained inside.

“Sometimes a scan can guide prep work, revealing the structure of the specimen within the matrix, making the process a little easier,” says O’Leary. “In other situations it may preclude the need to prepare a specimen, particularly one that may be too delicate for manual preparation. But for many specimens, you will never take away the need for manual prep work.”

CT scans are a welcome development to fossil finessers like Balcarcel, whose work can be physically grueling, straining eyes and posture while the preparator prunes tiny particles of rock away from fossils for hours on end. Still, Balcarcel says nothing compares with the thrill of uncovering a fossil.

“Seeing something for the first time in millions of years, and sometimes a species that no one has ever seen before, is a really amazing feeling,” she says.

 

extract  ex · tract

  1. Advanced Definition
  2. Spanish Cognate
  3. Examples

Advanced Definition

transitive verb

  1. to remove or take out by use of force.

    The dentist extracted his tooth.

  2. to obtain with effort.

    The police extracted a confession from him.

  3. to separate or draw out (juice from a fruit, metal from an ore, or the like) by pressure, distillation, or chemical action.

    The machine extracts the juice from the lemons.

  4. to excerpt from some piece of writing.

    The teacher extracted an important paragraph from the book and read it to the class.

  5. to derive (satisfaction, comfort, or the like), usu. from some event or circumstance.

    She had to admit that she extracted some pleasure from her seeing her sister get in trouble.

  6. in mathematics, to calculate (the root of a number).

noun

  1. a condensation and concentration of a substance.

    The coffee bread is flavored with almond extract.

  2. an excerpt from something written.
  3. something extracted.

Spanish cognate

extraer: The Spanish word extraer means extract.

These are some examples of how the word or forms of the word are used:

  1. They have the power and ability to extract natural resources from the earth.
  2. Coltan and other valuable minerals in Sud-Kivu province lie close to the surface and are easily extracted.
  3. The Roman Empire also learned how to mine gold. Ancient Romans built waterwheels and diverted streams of water to extract gold from rivers.
  4. Researchers have made attempts to extract silk strands from living silk worms in order to quell activists’ complaints, but the worms resist and grip the strands even harder, causing them to break.
  5. As it cools to the freezing point, sea ice forms with the “salts” extracted from the frozen water making the water below more dense. The very salty water sinks to the ocean floor.
  6. Meanwhile, one of Burland’s students, Helen Edmonds, was lab-testing a possible solution called soil extraction. Small amounts of soil would be removed from underneath the higher northern side of the leaning tower, letting the ground there gradually settle.
  7. The rock blasted out of these caverns is trucked to the surface, where it is crushed and gold is extracted. Currently, surveyors must use a laser-mapping device attached to a boom, and stick it as far into the cavern as possible.
  8. The Ancient Greeks used gold as a form of currency and mined the metal throughout the Middle East and the Mediterranean. The Roman Empire also learned how to mine gold. Ancient Romans built waterwheels and diverted streams of water to extract gold from rivers.
  9. Bone marrow is spongy tissue at the center of bones that produces new blood cells, including immune cells. A needle is inserted into the donor’s pelvic bone, and the marrow is extracted with a syringe. The donor’s body replaces the depleted bone marrow within weeks.
  10. New technologies for tapping trees are always being developed so producers can extract more and more sap. However, some things are beyond their control. The amount of sap that a maple producer is able to collect in any given year is largely dependent on the weather.

 

 

Wednesday’s Reading Answers

Comprehension Questions

1. What are fossils? 
  1. dinosaurs that were once thought to steal eggs out of nests
  2. feathers that the Citipati dinosaur may have had on its arms
  3. remains of ancient life that are usually buried in rock
  4. s-shaped necks and other similarities between birds and dinosaurs

2. To organize this text, the author has divided it into sections. In the section called “Egg Thief or Egg Protector?” what does the author compare to Citipati
  1. Tyrannosaurus rex
  2. living birds
  3. leaf prints
  4. fossil eggs

3. Birds are theropod dinosaurs.What is one piece of evidence that supports this theory? 

  1. Tyrannosaurus rex and Citipati were theropod dinosaurs.
  2. Some extinct theropod dinosaurs laid eggs, just like birds do today.
  3. Birds have feathers, but not all extinct theropod dinosaurs had feathers.
  4. Scientists once thought that some theropod dinosaurs were egg thieves.

4. The author describes Citipati dinosaurs as “caring parents.” What evidence supports this description? 
  1. Citipati walked on two feet with their legs directly underneath them.
  2. Citipati and Oviraptors are known as “oviraptorids,” which means “egg thieves.”
  3. Citipati laid eggs, had three-toed feet with claws, an s-shaped neck, and hollow bones.
  4. An adult Citipati was discovered sitting on a nest with its arms spread to protect the eggs.

5. What is the main idea of this text? 
  1. Fossils can form from teeth, shells, bones, footprints, leaf prints, and eggs.
  2. In 1923, a team of scientists from the American Museum of Natural History made a surprising discovery in the Gobi Desert.
  3. Theropods are a group of dinosaurs that included Tyrannosaurus rexVelociraptor, and Citipati.
  4. Discovering fossils of extinct dinosaurs helped scientists figure out that birds are a kind of dinosaur.

6. Read these sentences from the text.“Scientists compare fossils from different time periods to investigate how life on Earth has changed over time.“Think of fossils like puzzle pieces. The more pieces you have, the easier it is to put them together and tell what the whole picture looks like. And sometimes when you find and add new pieces, the picture looks very different from how you thought it would be.”

Why might the author have compared fossils to puzzle pieces? 

  1. to help readers understand how scientists use fossils
  2. to prove that being a scientist is hard work
  3. to argue that studying fossils is more fun than putting together puzzles
  4. to explain why some puzzles are more difficult than others

7. Read these sentences from the text.“Scientists discovered that like birds, theropods laid eggs. And they walked on two feet with their legs directly underneath them.”What or whom does “they” refer to here?

  1. “Scientists”
  2. “birds”
  3. “theropods”
  4. “eggs”

8. Read these sentences from the text.

“In 1923, a team of paleontologists from the American Museum of Natural History made a surprising discovery in Mongolia’s Gobi Desert. They found three large rocks that turned out to be fossilized dinosaur eggs. Then they discovered another fossil nearby: a toothless dinosaur.”

What did the leader of this expedition guess the dinosaur had been doing?

Suggested answer: The leader of the expedition guessed the dinosaur had been stealing the eggs from the nest.

9. Describe the adult Citipati fossil that led scientists to realize “oviraptorids” were caring parents. Support your answer with information from the text. 

Suggested answer: Answers may vary in detail but should reflect the text. For example: The adult Citipati fossil was brooding over a nest “the same way birds do: with its arms spread out to protect the eggs.”

 

10. The title of this text is “Piecing Together the Story of Dinosaurs from Fossils.” Its author compares studying fossils to putting together a puzzle. Later, the author writes, “Think of fossils like puzzle pieces. The more pieces you have, the easier it is to put them together and tell what the whole picture looks like.”

Explain how “piecing together” fossils has helped scientists learn more about dinosaurs. Be sure to discuss the adult Citipati fossil discovered in the Gobi Desert. Support your answer with information from the text. 

Answers may vary but should be supported by the text and discuss the adult Citipati fossil. For example:

In 1923, a group of scientists discovered a few “puzzle pieces” in the Gobi Desert. The pieces were three fossilized dinosaur eggs and the fossil of a toothless dinosaur nearby. The group’s leader concluded that the toothless dinosaur had been stealing the eggs. Later on, more fossils were discovered in the same desert. One of them was the fossil of an adult Citipati. It was found brooding over a nest “the same way birds do: with its arms spread out to protect the eggs,” according to the text. By “piecing together” the new fossils with the old ones, scientists realized that the earlier conclusion about “oviraptorids” had been wrong. These dinosaurs didn’t steal eggs after all. They protected eggs by sitting on nests with their arms spread out.

Students may also discuss other pieces of skeletal evidence (for example, hollow bones) that scientists have pieced together to learn about dinosaurs.