#Amniota

[wingedjewels]

Munchique Wood-Wren by Jay Packer Via Flickr: Endemic to the western Andes of Colombia, this highly sought-after wood-wren is found at higher elevations than the similar Gray-breasted Wood-Wren. Montezuma Road, Tatamá National Park, Colombia

[synblr]

A Prologue to Amniotes

Part IV - The egg came first

Late Mississippian. It has been 40 million years since tetrapods first walked on land. Every generation since then, they have remained bound to the waters for at least one moment in their life cycle.

Despite their adaptations for walking on land, early tetrapod reproduction wasn't much different from that of their fish predecessors. Spawning, or external fertilization of an egg mass, with eggs covered in a gelatinous membrane laid in a body of water, prevending the permeable eggs from dessicating.

But things are now changing. While the mid-Carboniferous rainforests still provide safe, moist environments, reptiliomorphs have already begun adventuring further inland. As swamps left room to humid crevices to lay eggs in, creatures like Casineria also began to develop internal fertilization, refusing to leave their reproduction at the mercy of the elements.

Casineria kiddi, an early amniote relative by ДиБгд (CC-BY-SA 4.0)

Adventuring into even drier environments, ancestors of amniotes still had to solve two crucial problems. While a harder shell could prevent the egg from dessicating, it would doom the embryo to suffocation, by preventing it to get rid of carbon dioxide. Furthermore, the small size of the eggs - also constrained by gas exchange - limited the full development of the embryo before hatching.

To solve both of these issues, the outer layers of the eggs would have to be reshaped. The outer gelatinous layer was replaced by a fibrous membrane for protection, and later by the three layers known as extraembryonic membranes: the amnion, chorion and allantois. The innermost amnion would surround and protect the embryo, while the outer chorion and sac-like allantois take care of gas exchange and waste removal.

In the safety of the amniotic egg, the embryo was able to hatch considerably more developed than before. Skipping the larval stage, amniote youngs would hatch as miniatures of the adults, making them able to face the challenges of the Carboniferous world from the day of their birth.

Structure of the amniotic egg, by Lumen Learning (CC-BY)

As the Pennsylvanian began and climate started to dry out, later developments would perfect the ability of early amniotes to survive in drier, fully terrestrial environments. A thicker, less permeable skin will develop, incorporating keratin and preventing dessication. Cutaneous respiration, requiring the skin to be moist at all times, will give way to costal respiration, harnessing the power of the ribcage to expand and contract the lungs. Cutting their last ties with the water, amniotes had finally conquered the land.

On one fateful day, not long after the amniote body plan was perfected, one of the most decisive splits in vertebrate history would occur. A divergence of the amniotes into two major lineages, alternating domination of land, sea and sky for the next 320 million years. But sauropsids like Hylonomus would at first stay in the shadows. The stage of the Late Pennsylvanian would be left to their rivals and cousins, as forerunners like Archaeothyris paved the way for their own lineage: the synapsids.

Archaeothyris, one of the first known synapsids, by ArthurWeasley (CC BY-SA 3.0)

[archipithecus]

found a decapitated wild rabbit in a neighbor’s yard, pics under the cut

[500tabsopenatonce-500tabso-pen]

New day, tree time!

guys i just found out about this site that does a daily guessing game, it’s phylogenetic wordle- so fun!!!

[a-dinosaur-a-day]

Birds are class Aves.

Sure, under Linnaean taxonomy. But, well,

A) Linnaeus was a eugenecist so his scientific opinions are suspect and his morality is awful

B) he didn't know about evolution

C) he didn't know about prehistoric life

so his classification system? Sucks ass. It doesn't work anymore. It no longer reflects the diversity of life.

Instead, scientists - almost across the board, now - use Clades, or evolutionary relationships. No rankings, no hierarchies, just clades. It allows us to properly place prehistoric life, it removes our reliance on traits (which are almost always arbitrary) in classifying organisms, and allows us to communicate the history of life just by talking about their relationships.

So, for your own edification, here's the full classification of birds as we currently know it, from biggest to smallest:

Biota/Earth-Based Life

Archaeans

Proteoarchaeota

Asgardians (Eukaryomorphans)

Eukaryota (note: Proteobacteria were added to an asgardian Eukaryote to form mitochondria)

Amorphea

Obazoa

Opisthokonts

Holozoa

Filozoa

Choanozoa

Metazoa (Animals)

ParaHoxozoa (Hox genes show up)

Planulozoa

Bilateria (all bilateran animals)

Nephrozoa

Deuterostomia (Deuterostomes)

Chordata (Chordates)

Olfactores

Vertebrata (Vertebrates)

Gnathostomata (Jawed Vertebrates)

Eugnathostomata

Osteichthyes (Bony Vertebrates)

Sarcopterygii (Lobe-Finned Fish)

Rhipidistia

Tetrapodomorpha

Eotetrapodiformes

Elpistostegalia

Stegocephalia

Tetrapoda (Tetrapods)

Reptiliomorpha

Amniota (animals that lay amniotic eggs, or evolved from ones that did)

Sauropsida/Reptilia (reptiles sensu lato)

Eureptilia

Diapsida

Neodiapsida

Sauria (reptiles sensu stricto)

Archelosauria

Archosauromorpha

Crocopoda

Archosauriformes

Eucrocopoda

Crurotarsi

Archosauria

Avemetatarsalia (Bird-line Archosaurs, birds sensu lato)

Ornithodira (Appearance of feathers, warm bloodedness)

Dinosauromorpha

Dinosauriformes

Dracohors

Dinosauria (fully upright posture; All Dinosaurs)

Saurischia (bird like bones & lungs)

Eusaurischia

Theropoda (permanently bipedal group)

Neotheropoda

Averostra

Tetanurae

Orionides

Avetheropoda

Coelurosauria

Tyrannoraptora

Maniraptoromorpha

Neocoelurosauria

Maniraptoriformes (feathered wings on arms)

Maniraptora

Pennaraptora

Paraves (fully sized winges, probable flighted ancestor)

Avialae

Avebrevicauda

Pygostylia (bird tails)

Ornithothoraces

Euornithes (wing configuration like modern birds)

Ornithuromorpha

Ornithurae

Neornithes (modern birds, with fully modern bird beaks)

idk if this was a gotcha, trying to be helpful, or genuine confusion, but here you go.

all of this, ftr, is on wikipedia, and you could have looked it up yourself.

[jomindraws]

Alright here's the very first batch of alien animals we have, first 7 classes out of 120. Starting off with Superphylum Near Bilateral

(AN1) Clade: Nephrozoa

A clade of animals that possess a distinct oral and anal end during the first stage of development.

(AN1 A) Clade Bilatera

A clade of animals that are symmetrical on either side of the sagittal plane and retain their oral and anal ends throughout most of their lifetime.

Superphylum Near Bilateral

A taxa of animals possessing a solidified nerve structure or adjacent notochord-analogous structure in the initial stage of development; occupying terrestrial or the upper stratification of the aquatic biosphere.

(AN1 A1) Clade Quasichordata

A clade of near bilaterans that possess a dorsal fibrous nerve column functionally similar to a notochord at some point in their life cycle.

PHYLUM ENDOSPINAL CHORDATA

Phylum contains a notochord at some point in the life cycle, with an internal dense skeleton made typically of bone or cartilage. Gametangia positioned posterior to abdominal tagma. Dermal protection by mucus membrane or keratin.

(AN1 A1-a) Clade Amniota

Clade using amniotic fluid to support, protect, and provide nutrients to embryos.

(AN1 A1-ai) Clade Reptilia (Includes Mammalian Reptiles and Non-Mammalian Reptiles)

Clade of amniotes that possess an outer dermal layer of scale plates, a mineralized skeleton of bone, defense structures of keratin, and a coccyx that extends into a posterior tail.

Class Mammalian Reptiles

Class of reptiles that maintain heat through endothermy, give live birth to young, possess mammary glands, and typically dual integumentation.

Class Non-Mammalian Reptiles

Class of reptiles that maintain heat through exothermy, develop young through eggs, possess yolk inside eggs, and typically have single integumentation.

(AN1 A1-aii) Clade Membrana (Includes Membranous Dermates)

Clade of amniotes that possess an outer dermal layer of mucosal membrane, an internal skeleton of cartilage, and an internal circulation structure consisting of a hemocoel.

Class Membranous Dermates

Class of membranes that develop only an outer mucus membrane for protection and do not use shells or rocks to protect themselves.

(AN1 A1-aiii) Clade Pescada (Includes Cartilage Fish and Bone Fish)

Clade of amniotes that possess an outer dermal layer of keratin scales and a passive respiration through gills.

Class Cartilage Fish

Class of pescada that have an internal skeleton of cartilage and do not have fixed jaws.

Class Bone Fish

Class of pescada that have an internal skeleton of bone and have fixed jaws.

(AN1 A1-b) Clade Cephalopoda (Includes Cephalopodal)

Clade using a mucosal sac to house embryos and transfer from a polyp to a medusoid stage.

Class Cephalopodal

Class using a mucus membrane, a ringed oral and anal end, and six dense muscled tentacles for movement.

(AN1 A1-c) Clade Oothecae (Includes Exoskeletal Endoskeletal)

Clade using ootheca ovoviviparity which detaches before maturity.

Class Exoskeletal Endoskeletal

Class utilizing both an internal mineralized skeleton in tandem with a dense plated mineralized exoskeleton.

[istherewifiinhell]

50 metazooa win (53 games)

one of the funnier trees/series of guesses

[ID: The metazooa, a cladistics puzzle tree, guessed in 6. Starting with parakett under amniota, then mouse under euarchontoglires. Under homininae is human then gorilla. And finally under pan is chimpanzee then the answer, bonobo. END]

like. they did some monty hall shit to me

Pan (genus)

The genus Pan consists of two extant species: the chimpanzee and the bonobo. Taxonomically, these two ape species are collectively termed panins.

good on me for specificity? completionism?

[metazooa-everyday]

Introduction

Hi! You can call me void, my pronouns are they/them. I wanted to make a short intro to tell you what this blog is about.

If you don't know, metazooa is a game where you have to guess the animal of the day, by going through a tree where each guess tells you the closest common groups between the animals (eg: Laurasiatheria, Amniota). I decided to make this blog, somewhat inspired by the art everyday accounts i've seen on here, where I will draw the animal of the day hopefully everyday if I can. I will also share my score of the day, using the format m[total amount of guesses]/[amount of mistakes] (eg: m6/2). The posts will likely be made towards the end of the day (GMT) as to avoid spoiling the answer for anyone.

I hope anyone who finds this blog and follows along enjoys the journey, and that you have a good rest of your day/night.

-Void

[10blue10]

HTTYD: Dragon Taxonomy

Kingdom: Animalia 

Phylum: Chordata 

Clade: Amniota

Clade: Synapsida 

Clade: Therapsida 

Clade: Dercomaiia 

Clade: Draconomorpha 

Class: Dracontes 

Superorders: 2

Orders: 8

Families: 26

Superorder 

Order 

Family

Gronckle 

Hotburple 

Quaken  

Goregutter 

Red Death 

Bewilderbeast 

Cavern Crasher 

Family 

Eruptodon 

Sentinel 

/

Order 

Family

Mudraker 

Thunderclaw

Family 

Snow Wraith  

Snifflehunch 

Windgnasher 

Family 

Snafflefang 

Shovelhelm 

Moldruffle 

/

Order 

Family 

Hideous Zippleback 

Scauldron 

Family 

Hobgobbler 

Submaripper 

Family 

Buffalord 

/

Order 

Family 

Night Fury 

Light Fury 

Sand Wraith 

Woolly Howl 

Family 

Stormcutter 

/

Order

Family 

Thunderdrum 

Shellfire 

Family 

Singetail 

Smothering Smokebreath  

Changewing 

Snaptrapper 

/

Order 

Family 

Flightmare 

Sweet Death

Shockjaw 

Firewyrm 

Thunderpede 

Flame Whipper 

Family 

Shadow Wing 

Family 

Sandbuster 

Slitherwing 

Family 

Grapple Grounder 

Grim Gnasher 

Family 

Egg Biter 

Deadly Nadder 

Scuttleclaw 

Family 

Dramillion 

Family 

Rumblehorn 

Triple Stryke 

Deathgripper 

/

Superorder 

Order 

Family 

Razorwhip 

Windstriker 

Death Song 

Slithersong 

Family 

Devilish Dervish 

Thornridge 

Threadtail 

 Family 

Monstrous Nightmare

Armorwing 

Boneknapper 

Night/Cave/Fire Terror 

Prickleboggle 

Terrible Terror 

Family 

Typhoomerang 

Silver Phantom 

Timberjack 

/

Order

Family 

Sword Stealer 

Shivertooth 

Windwalker 

Groncicle 

Hackatoo 

Seashocker

Family 

Hobblegrunt 

Skrill 

Whispering Death 

Screaming Death 

Family 

Raincutter 

Sliquifier 

Tide Glider 

Speed Stinger 

[temeraire]

within the taxonomic group of vertebrates (animals with a backbone), amphibia is the sister clade of amniota. amniota includes synapsids such as mammals and sauropsids such as reptiles. in the christian bible, original sin took place when the devil in the form of a snake (sauropsid) convinced a human (synapsid) to eat an apple. the participants of original sin were only within the clade amniota, meaning that amphibians had nothing to do with sin and are, i propose, free from the judgement of the christian god

[wingedjewels]

Green-and-black Fruiteater by Jay Packer Via Flickr: Reserva Ecológica Río Blanco, Colombia

[yo-sostenible]

Te leemos las noticias aquí Las tortugas de cuello oculto Apalone spinifera y Staurotypus triporcatus, cuyo genoma ha sido ensamblado. / Nicole Valenzuela Un equipo internacional de científicos han ensamblado los genomas de dos especies de tortugas de cuello oculto inéditos hasta ahora. Los resultados contribuirán al desarrollo de estrategias más efectivas de conservación de estos animales y al estudio de la evolución del genoma y la organización cromosómica en los vertebrados. Un estudio liderado por las investigadoras Aurora Ruiz-Herrera (UAB) y Nicole Valenzuela de la Universidad Estatal de Iowa (EE UU), con la participación del Instituto de Biología Evolutiva (CSIC-UPF) y del Earlham College, destaca la importancia del papel de la cromatina —la estructura tridimensional en la que el material genético se pliega y empaqueta dentro del núcleo de la célula— en la regulación de la función los genes y su impacto en la evolución y especiación. Las investigadoras han ensamblado de novo (sin un modelo de referencia previo) el genoma completo de dos especies de tortugas criptodiras, comúnmente denominadas tortugas de cuello corto, combinando tecnologías de secuenciación y expresión de genes. Se trata de dos linajes en los que los cromosomas sexuales han evolucionado de forma independiente: uno con cromosomas XX/XY (el tipo que tenemos los humanos y otros mamíferos) y el otro con cromosomas ZZ/ZW (presente en aves y mariposas). Además, han identificado una nueva conformación tridimensional de la cromatina en ambos linajes: más allá de los eventos de fusión y fisión en los genomas lineales, han detectado un patrón de plegamiento cromosómico que permite interacciones entre los centrómeros y los telómeros. Los hallazgos aportan nuevas claves sobre la estructura 3D de la cromatina en amniotas, grupo filogenético al que pertenecen reptiles, aves y mamíferos. “Sugerimos que el patrón divergente encontrado en las tortugas se originó a partir de un estado existente en el ancestro de los amniotas que presentaba una configuración nuclear con asociaciones extensas entre sus cromosomas. Estas asociaciones se preservaron durante el reordenamiento del genoma lineal en tortugas y otros vertebrados”, afirma Valenzuela. Ruiz-Herrera de la UAB, destaca: “Los hallazgos amplían nuestro conocimiento sobre la evolución de los cromosomas sexuales y ofrecen una base sólida para futuras investigaciones sobre la evolución del genoma y la organización cromosómica en vertebrados”. Modelo clave para la investigación científica En el artículo, las investigadoras destacan que el estudio del genoma de las tortugas proporciona información crucial que podría transformar nuestra comprensión de la biología y la evolución. Su longevidad y resistencia a enfermedades las convierten en un modelo único para estudios científicos que abarcan desde la biomedicina hasta la conservación de especies. Descifrar su genoma es clave para identificar los genes responsables de estos rasgos, y podría permitir avanzar en la medicina humana, especialmente en áreas como el envejecimiento y la resistencia a enfermedades. Además, el genoma de las tortugas ofrece una ventana única a la evolución: estas especies de reptiles han existido durante más de 250 millones de años, es decir, han sobrevivido a eventos de extinción masiva y han sabido adaptarse a varios entornos. Estudiar su ADN ayuda a entender mejor los mecanismos de adaptación y supervivencia, claves para la conservación de las propias tortugas y también para otras especies en peligro. Los primeros ensamblajes de genomas de tortugas se publicaron hace más de una década. Desde entonces, se han reportado doce ensamblajes de genomas de quelonios, nueve de ellos con la secuencia de sus genes identificados. “Los nuevos ensamblajes generados se añaden ahora a esta lista y reflejan la importancia de los recursos genómicos de alta calidad para el avance de la biología evolutiva y del desarrollo”, concluye R...

[myhorrorstory]

nosso co ancestral em comum com os sapos viveu no fim do devoniano, inicio do carbonifero, ha 350 milhões de anos. fazemos parte do mesmo grupo, amniota.

Os amniotas são caracterizados por possuírem uma membrana amniótica que envolve o embrião, formando o saco amniótico. O líquido amniótico, presente na cavidade do âmnio, protege o embrião de choques mecânicos, desidratação e patógenos. Além disso, permite que o feto se movimente e se desenvolva muscularmente. junto com os anfíbios, fazemos parte de um grande grupo chamado tetrapoda, animais de quatro membros.

[dropsofsciencenews]

La Salamandra Gigante que Reescribe la Historia de los Tetrápodos

ENG version ITA version

Cuando abrimos libros de paleontología y viajamos atrás en el tiempo entre nuestros ancestros, encontramos que los tetrápodos, los primeros vertebrados de cuatro patas, a menudo se describen como animales estrechamente vinculados a los humedales ecuatoriales del período Carbonífero, que abarcó desde hace 358.9 hasta 298.9 millones de años. A medida que seguimos leyendo, descubrimos que durante el Carbonífero tardío, alrededor de hace 307 millones de años, los tetrápodos más arcaicos fueron rápidamente reemplazados por los ancestros de los amniotas modernos (vertebrados con huevos amnióticos, como reptiles, dinosaurios, aves y mamíferos) y los lisanfibios (anfibios modernos como ranas, salamandras y cecilias). Estas hipótesis se basan principalmente en fósiles encontrados en la región paleoequatorial de Pangea, conocida como Laurussia, que incluía América del Norte y Europa.

Sin embargo, un descubrimiento inesperado en Namibia sugiere una distribución más global de este grupo de animales. Un equipo de investigación liderado por los doctores Claudia A. Marsicano y Jason D. Pardo encontró restos fósiles en el valle del río Ugab, en Damaraland, conservados en la piedra fangosa de un antiguo lago de agua dulce. Los restos han sido datados en 280 millones de años, justo al comienzo del período Pérmico, y provienen de depósitos de alta paleolatitud (aproximadamente 55° S), una región que formaba parte del supercontinente Gondwana. La datación y la ubicación única de este hallazgo demuestran que los tetrápodos ya estaban bien establecidos en las latitudes templadas-frías de Gondwana durante las etapas finales de la desglaciación del Carbonífero-Pérmico.

Al descubrir los restos, los investigadores inmediatamente se dieron cuenta de que este antiguo tetrápodo representaba una nueva especie, que ha sido nombrada Gaiasia jennyae. El nombre se refiere a la Formación Gai-As y honra a Jenny Clack (1947-2020), una científica cuyas descubrimientos fueron fundamentales en el estudio de los primeros tetrápodos. El animal vivió durante el período Pérmico, mucho antes de la aparición de los primeros dinosaurios. Las características de Gaiasia jennyae indican que era un prototetrápodo, una forma de transición entre los peces y los primeros tetrápodos terrestres. Los fósiles, que incluyen un esqueleto casi completo de un adulto de unos 3 metros de largo, son los más grandes jamás descubiertos para este tipo de vertebrado. El análisis de los fósiles reveló una cabeza ancha y plana, de casi 60 centímetros de largo, unida a un cuerpo de 2.5 metros. La estructura del cráneo, adornado con colmillos inusualmente grandes y curvados, sugiere que este animal también era un formidable depredador, probablemente un cazador de peces en las aguas pantanosas y lagos de la región. Gaiasia jennyae todavía presenta rasgos acuáticos, como branquias y extremidades subdesarrolladas, que le permitían vivir tanto en el agua como en la tierra.

El descubrimiento de esta especie en Namibia es particularmente significativo ya que desafía la hipótesis anterior de que los primeros tetrápodos gigantes estaban confinados al hemisferio norte durante la transición del Carbonífero-Pérmico. Esta nueva perspectiva sugiere que adaptaciones significativas en la radiación inicial de los tetrápodos ocurrieron fuera de las cuencas bien muestreadas de la Pangea paleoequatorial. La diversificación y las dinámicas de extinción de los tetrápodos durante el Paleozoico tardío podrían, por lo tanto, haber sido mucho más complejas y globalmente extendidas de lo que se pensaba anteriormente.

fuente

[a-dinosaur-a-day]

yes, I know wikipedia says "reptilia" is a subset of sauropsida, but that is hardly a consensus/universal agreement. Plus, this is a silly tumblr poll, and I enjoy silliness. (Including an option does not mean I endorse it). Some pros and cons are below. don't worry, I plan on doing this for other holdover linnean names folks can't let go of - fish, amphibian, bird, mammal, bug...

Pro to Reptiliomorpha: no way you're leaving anything out Con to Reptiliomorpha:

Pro to Amniota: "mammal-like reptile" stays Con to Amniota: it is absolute madness to consider mammals reptiles, that is such a deep divergence

Pro to Sauropsida: mammals are left out, as are all synapsids, but most things called reptiles stay in (as do birds) Con to Sauropsida: people will still call Dimetrodon a reptile and we will never know peace

Pro to Eureptilia: excluding parareptiles which are just weird enough that you could do it Con to Eureptilia: it's somewhat arbitrary and excludes a bunch of things we'd call reptiles today

Pro to Diapsida: being a diapsid is usually considered a major feature of reptiles, esp now we know turtles evolved from diapsids Con to Diapsida: it's somewhat arbitrary and excludes a bunch of things we'd call reptiles today

Pro to Sauria: crown group of living reptiles Con to Sauria: ichthyosaurs (maybe) & a bunch of other reptile like things are excluded

Pro to Lepidosauromorpha: birds aren't called reptiles Con to Lepidosauromorpha: crocodiles, turtles, pterosaurs, nonavian dinosaurs, and many more aren't reptiles

[immoren]