Caracteristicas chave dos dinossauros

O que é um dinossauro? É um animal do grupo dos Dinosauria Owen, 1842. Por definição é o último ancestral comum do Triceratops horridus, do Passer domesticus, do Diplodocus carnegii e de todos os seus descendentes (Baron et al, 2017).

Já as características anatómicas que os distinguem dos outros répteis são:

1. Fossa supratemporal em frente à fenestra supratemporal; 
2. Epipófises presentes; 
3. Rádio menor que 80% do comprimento do úmero; 
4. Dígito manual semi-oposição I; 
5. Dígitos manuais reduzidos IV & V; 
6. Acetábulo aberto (perfurado).

Características distintivas dos dinossauros.

E estas são as características chave os principais grupos de dinossauros:

Clado	Características chave
Archosauria	Pescoço com curva em forma de S; Tíbias e metatarsos longos; Fenestra antorbital e mandibular;
Dinosauria	Fossa supratemporal em frente à fenestra supratemporal; Epipófises presentes; Rádio menor que 80% do comprimento do úmero; Dígito manual semioposição I; Dígitos manuais reduzidos IV & V; Acetábulo aberto (perfurado)
Ornithischia	Pelvis opistopúbica; Osso predental; Osso palpebral; Fenestras antorbitais reduzidas ou mesmo fechadas; Articulações da mandíbula abaixo do nível dos dentes; Dentes largos em forma de folha com grandes dentículos; 5 ou mais vértebras sacras
Thyreophora	Osteodermes parasagitais com quilha na face dorsal do tronco
Stegosauria	Espigões na cauda e osteoderme axiais como placas largas
Dacentrurinae	Pescoço longo; Placas em pares; Costelas e vértebras cervicais fundidas
Ankylosauria	Membros curtos; Osteodermos abundantes, inclusive no crânio e na mandíbula; Suturas cranianas obliteradas e anquilosadas
Neornithischia	Camada mais espessa de esmalte assimétrico no interior dos dentes inferiores
Ornithopoda	Púbis longo que se estende além do ílio; Bico córneo; Sem fenestra mandibular
Iguanodontia	Sem dentes pré-maxilares; Coroas dentárias Losangulares; 6 ou mais vértebras sacrais
Ankylopollexia	Polegar suporta espigão cónico
Saurischia	Articulações adicionais (hyposfeno-hipantro) nas vértebras dorsais
Sauropodomorpha	Aumento do tamanho corporal; Diminuição do tamanho do crânio; Pescoço longo
Sauropoda	Narina na superfície dorsal do crânio; Vértebras pré-sacrais com extensos pleurocoels; 12 ou mais cervicais; Redução no número de falanges da mão; Manus apenas com garra (falange ungeal) no digito I
Eusauropoda	Pescoço alongado: cervicalização da vértebra dorsal e a adição de duas vértebras cervicais
Neosauropoda	Fenestra pré-antorbital; dentes sem dentículos; dois ou menos carpais; extremidade tibial subcircular; Dentes na frente do focinho; Narinas colocados dorsalmente; Metacarpo colunar
Diplodocidae	Cauda longa e em chicote; Narina retraída que se uniram acima da órbita; Crânios longos; Membros anteriores curtos
Macronaria	Narinas grandes; Corpo distais isquiais quase coplanares.
Titanosauriformes	Facetas de desgaste dentário acentuadamente inclinadas em relação ao eixo labio-lingual; Costelas dorsais anteriores, largas e tabulares; Vértebras dorsais com lâmina centroparapofisárias posterior
Ornithoscelida	Forame pré-maxilar anterior; Diastema; Crista aguçada na maxila; Jugal excluído da fenestra antorbital; Quadrado orientado anteroventralmente; Processos paroccipitais alongados; Forâme na superfície lateral do dentário; Trocânter anterior expandido e parcialmente separado da diáfise femoral
Theropoda	Mandíbula cinética e flexível; 5 ou mais vértebras sacras; mão: Dígito V ausente (mão de 4 dedos); Falanges do dígito V do pé ausente; Pé: Dígito I reduzido e sem contato com a articulação do tornozelo; Clavículas fundidas
Neotheropoda	Fenestra no lacrimal; Dentes pré-maxilares simétricos; Parte anterior expandida do ílio; Número reduzido de dentes maxilares
Ceratosauria	Púbis e ísquios fundidos ao ílio em adultos
Tetanurae	Dentes posteriores em posição anterior (antes do lacrimal)
Megalosauroidea	Presença de pós-orbital: Processo jugal em forma de U
Coelurosauria	Carpal hemi-circular; Mãos longas e esguias; Protopenas; Esterno ósseo sólido
Maniraptora	Cauda rígida distalmente; Membros anteriores pelo menos ¾ comprimento da coluna vertebral pré-sacral; Parte frontal da expansão púbica ausente; comportamento de chocar; Longas penas nos braços
Aves	Vôo activo; Membro anterior mais longo do que o membro posterior

Baron, Matthew G.; Norman, David B.; Barrett, Paul M. (22 March 2017). "A new hypothesis of dinosaur relationships and early dinosaur evolution". Nature. 543 (7646): 501–506. Bibcode:2017Natur.543..501B. doi:10.1038/nature21700
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Árvore dos dinossauros é abanada, com mudança radical na classificação

Até agora a classificação dos dinossauros tem sido estável numa coisa: o grupo Dinosauria divide-se em Ornithischia e  Saurischia. Mas toda essa sistemática é agora posta em causa num novo artigo publicado na revista Nature por Matthew G. Baron, David B. Norman e Paul M. Barrett "A new hypothesis of dinosaur relationships and early dinosaur evolution".

Nesta nova hipótese, os terópodes e os ornitísquios são um grupo-irmão (os Ornithoscelida) separado dos sauropodomorfos que começam a incluir Herrerasaurus. Isto é um grande abanão na árvore dos dinossauros, com rearranjo de grupos que se julgavam estáveis. Esta classificação muda todos os livros clássicos sobre dinossauros.

LINK

As novas definições dos clados passam a ser:

Dinosauria: The least inclusive clade that includes P. domesticus, T. horridus and D. carnegii

Ornithoscelida: The least inclusive clade that includes P. domesticus and T. horridus

Saurischia: The most inclusive clade that contains D. carnegii, but not T. horridus

Theropoda: The most inclusive clade that contains P. domesticus, but not D. carnegii or T. horridus

Ornithischia: The most inclusive clade that contains T. horridus, but not P. domesticus or D. carnegii

Sauropodomorpha: The most inclusive clade that contains D. carnegii,but not T. horridus, P. domesticus or H. ischigualastensis

Herrerasauridae: The least inclusive clade that includes H. ischigualastensis and Staurikosaurus pricei.

E algumas das sinapomorfias dos Ornithoscelida:

1, anterior premaxillary foramen; 2, diastema; 3, sharp ridge on maxilla; 4, jugal excluded from antorbital fenestra;5, anteroventrally oriented quadrate; 6, elongate quadrate–squamosal contact; 7, elongate paroccipital processes; 8, post-temporal foramen enclosed within paroccipital processes; 9, supraoccipital that is taller than it is wide; 10, foramen on lateral surface of dentary; 11, straightretroarticular process; 12, scapula, length>3× distal width; 13, ventrally bowed humerus; 14, open acetabulum; 15, broadened anterior trochanter, partially separated from femoral shaft; 16, fibular crest; 17, oblique distal surface of tibia; 18, fusion of distal tarsals to metatarsals.

Osteologia de lagartos europeus

Saiu um novo trabalho liderado por Andrea Villa que se debruça sobre osteologia, registo fóssil e paleobiodiversidade de lagartos europeus. 
O estudo  publicado na revista Amphibia-Reptilia e que também contou com a participação do nosso colaborador Emanuel Tschopp confirma, com dados osteológicos, a monofilia do género Lacerta que, em Portugal, inclui o lagarto-de-água Lacerta schreiberi. O sardão, previamente denominado Lacerta lepida, é o outgroup, e com o nome Timon lepidus.

"Lacertilia", desenhado por Ernst Haeckel
publicado no Kunstformen 
der Natur, 1904

Abstract. The capability of palaeontologists to identify fossil remains of a particular group of vertebrates strongly depends on the knowledge they have of its comparative osteology and on the actual presence of diagnostic differences among the considered taxa. This could have a relevant influence on the study of palaeodiversity, since a low recognisability causes a loss of data when trying to reconstruct the history of taxa that lived on Earth in the past. Currently, more than 6000 extant species of lizards and worm lizards are known, and new ones continue to be discovered, mainly based on molecular data. But are we able to recognise this high diversity using osteology? As far as European taxa are concerned, the osteological recognisability of non-snake squamates is very low: only 31% of the extant European taxa can be identified based on their skeletal morphology.
This is balanced partially by the fact that most recognisable taxa have been actually recognised in the fossil record, suggesting that the lost data are mainly due to the scarce knowledge of the comparative osteology of these reptiles and less influenced by other biases, such as taphonomic or collection biases. In this context, specimen-level phylogenetic analysis has proved to be a useful tool to identify diagnostic combinations of osteological features, at least for lacertid species, as evidenced by a case study focused on the genus Lacerta.

Filogenia do género Lacerta (Villa et al., 2017)

Villa, A., Tschopp, E., Georgalis, G.L. and Delfino, M., 2017. Osteology, fossil record and palaeodiversity of the European lizards. Amphibia-Reptilia, 38(1), pp.79-88. PDF

http://booksandjournals.brillonline.com/content/journals/10.1163/15685381-00003085 

Curso de filogenia para paleontologia (Março na FCT-NOVA)

"Filogenia para Paleontologia" é o curso/formação de introdução à análise filogenética com base em parcimónia para estudos de paleontologia e de morfologia ministrado no fim de semana de 12 e 13 de Março pela Universidade Nova de Lisboa (link) e aberto a todos os interessados. 

Segue aqui os detalhes do curso:

Training course: Phylogeny for Paleontology (March 12-13, 2016)

This is a two day introductory course on parsimony-based phylogenetic analysis in paleontology and morphological studies, for students and proffesionals, to be held at the Departamento de Ciências da Terra, Universidade de Nova Lisboa.

Aim of the course: Phylogenetic analyses are a key tool for paleontologists. The aim of this course is to provide the participants the basic skills need to perform a morphological phylogenetic analysis and publish their  results. The basics of parsimony analysis and character optimisation will be covered.

Target public and credits: Open to anyone but targeted to students and professionals in evolutionary biology and paleontology. Diploma will be provided by FCT-UNL. This training can be included as supplement to the graduation or master diploma (accreditation still pending).

Instructors: Miguel Moreno Azanza and Octávio Mateus (FCT- University NOVA of Lisbon)

Requirements: All participants are required to bring their own laptop. Windows strongly recommended (MacOS versions of the software available but without user interface).

Dates and contents: The course will have three sessions, each with theoretical and practical lessons, plus and an additional optional workshop session to provide assistance with the attendees’ datasets. Total Hours of Training: 16h.

1st Day (March 12th)

Session 1: Introduction to cladistic analysis using parsimony-based methods.

Introduction to systematics, basic concepts, how to build a matrix and best practices.

Session 2: Introduction to parsimony-based software.

Introduction to TNT: Editing your matrix. Basic Searches. Consensus trees. Branch support. Getting trees ready to publish.

2nd day (March 13th)

Session 3: Intermediate-level use of parsimony-based software.

Continuous characters and mixed matrices. Weighting characters. New technology searchers.  Constrained searches. Basic scripts. Other stuff TNT can do.

Session 4: Workshop: bring your matrix to the lab (optional).

Participants will be allowed to bring their matrices to the lab, to be examined in a collaborative approach by the class.

Language: English (translation into Portuguese is available if necessary)

Place: Departamento de Ciências da Terra, Building IX, Universidade Nova de Lisboa, 2829-516 Caparica, Portugal

GPS Coordinates: 38.660734, -9.207075

https://www.google.com/maps/place/Departamento+de+Ciências+da+Terra,+DCT-FCT-UNL

Registration fees: Non student: 150 euros. Students of Universidade Nova de Lisboa (Mestrado de Paleontologia and others): free. Other student: 30 euros. (student card is required). Payment is done at the beginning of the course.  

Registration: Send an email to: Miguel Moreno-Azanza (mmazanza@fct.unl.pt) including your name, email, professional situation, institution and where you learn about this course, until March, 1st.

Questions can be addressed to: mmazanza@fct.unl.pt

Quantos Camarasaurus existem?

O dinossauro Camarasaurus é alegadamente um dos saurópodes mais bem conhecidos. Contudo, não se sabe exactamente se é apenas um género, quantas espécies estão neste género, nem sequer como as distinguir com rigor. Esta tem sido uma demanda a que se dedicou Emanuel Tschopp e colegas através de uma análise com base em espécimes em vez de espécies ou géneros.
O resultado é agora publicado preliminarmente no congresso 74th SVP, em Berlim.

Como principais conclusões: existe apenas um único género (o género Cathetosaurus afinal poderá não ser válido, ao contrário do que pensávamos), a família Camarasauridae é monofilética e tem um único género. Contudo, parece haver mais espécie do que as reconhecidas actualmente.

Tschopp, E., Mateus O., Kosma R., Sander M., Joger U., & Wings O. (2014). A specimen-level cladistic analysis of Camarasaurus (Dinosauria, Sauropoda) and a revision of camarasaurid taxonomy. Journal of Vertebrate Paleontology. Program and Abstracts, 2014, 241-242.

PDF

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Estudante de paleontologia Emanuel Tschopp

A Faculdade de Ciências e Tecnologia, da Univ. Nova, conta, desde há cerca de três anos, com um bolseiro de doutoramento a estudar dinossauros saurópodes, o suíço Emanuel Tschopp. Divulgamos assim o perfil de um estudante internacional de paleontologia radicado em Portugal e a viver na Lourinhã.

Emanuel Tschopp realizou o seu mestrado em paleontologia em 2008 na Universidade de Zurique, na Suíça. Em 2010, ele começou o seu doutoramento no Departamento de Ciências da Terra da Faculdade de Ciência e Tecnologia da Universidade Nova de Lisboa, Portugal, sob a supervisão do Prof Octávio Mateus. Seus principais interesses investigação são a filogenia e evolução dos dinossauros saurópodes, em particular das faunas do Jurássico Superior  da Formação de Morrison nos EUA e da Lourinhã em Portugal, onde também participou de várias campanhas de escavação.
E. Tschopp e O. Mateus descreveram recentemente uma nova espécie de saurópode, Kaatedocus siberi, e postulam sobre a existência do osso interclavícula em saurópodes que previamente se pensava ser ausente em dinossauros.
Os projetos em curso são a análise filogenética dos saurópodes diplodocídeos baseada em espécimes, uma revisão de Camarasaurus, e uma análise morfométrica 3D da coluna vertebral de saurópodes.

Tema de tese: Evolução dos dinossauros saurópodes diplodocídeos com ênfase em amostras de Howe Ranch (Wyoming, EUA)


Obras publicadas:

Tschopp, E., & Dzemski, G. (2012). 3-dimensional reproduction techniques to preserve and spread paleontological material–a case study with a diplodocid sauropod neck. Journal of Paleontological Techniques, 10, 1-8.

Tschopp, E., & Mateus, O. (2012). The skull and neck of a new flagellicaudatan sauropod from the Morrison Formation and its implication for the evolution and ontogeny of diplodocid dinosaurs. Journal of Systematic Palaeontology, (ahead-of-print), 1-36.

Tschopp, E., & Mateus, O. (2012). A sternal plate of a large-sized sauropod dinosaur from the Late Jurassic of Portugal. Fundamental, 20, 263-266.

Christiansen, N. A., & Tschopp, E. (2010). Exceptional stegosaur integument impressions from the Upper Jurassic Morrison Formation of Wyoming. Swiss Journal of Geosciences, 103(2), 163-171.

Tschopp, E., & Mateus, O. (2013). Clavicles, interclavicles, gastralia, and sternal ribs in sauropod dinosaurs: new reports from Diplodocidae and their morphological, functional and evolutionary implications. Journal of anatomy.

Tschopp, E., Russo, J., & Dzemski, G. (2013). Retrodeformation as a test for the validity of phylogenetic characters: an example from diplodocid sauropod vertebrae. Palaeontologia Electronica, 1998, 16.

Website: http://unl-pt.academia.edu/EmanuelTschopp

Porque não faz sentido usarmos os escalões Lineanos de filo, classe, ordem, etc

Quando o ilustre sueco Carl von Linné (ou Carolous Linnaeus, em latim, tal como ele assinava, ou Carlos Lineu, em português) classificou os organismos vivos, agrupou-as em ‘rankings’ ou escalões, que tendo sido ulteriormente adicionados ficaram com a clássica sequência Divisão, Reino, Filo, Classe, Ordem, Família, Género e Espécies.

Esta partimentação agrupa os seres vivos do mais abrangente até a uma única espécie. Assim, a Divisão pode ter vários Reinos, que por sua abrange vários Filos, que contêm várias Classes e assim por diante.

É um sistema prático e de alguma forma inspirado na hierarquia militar. Neste sistema, todas as espécies são arrumadas de forma que nenhuma esteja de fora da sequência Divisão, Reino, Filo, Classe, etc. Dito de outra forma, todas as espécies pertencem a um género, que está enquadrado numa família, que não pode deixar de estar numa ordem, até que todos os escalões estão preenchidos.

É, sem dúvida, um sistema fácil e prático, como se coordenadas de um endereço se tratasse. Era como se arrumássemos as espécies em gavetas, que estão contidas em estantes, que por sua vez estão em armários, em salas, casa, ruas, bairros, etc. Prático e simples… contudo a Natureza não funciona assim, sendo a realidade bem mais complexa. Linné usou esta classificação pois não conhecia a evolução das espécies (conceito que foi avançado após a sua morte por Lammarck e outros, e melhor compreendido e explicado por C. Darwin). Se Linné compreendesse a evolução, decerto que saberia que não podemos agrupar os organismos em secções discretas, como se de objectos físicos se tratassem devidamente arrumadas no sistema de gavetas, prateleiras, armários, etc.

As espécies são contínuas, e todos os organismos actuais fazem parte de uma corrente reprodutiva de pais para filhos, desde há 3.600 milhões de anos, sempre com pequenas alterações graduais e contínuas. Se reconstruirmos a linhagem de todas as espécies, vamos ter algo mais parecido a uma árvore, em que cada espécie é uma folha ou uma célula, do que a um armário (usando a analogia das gavetas).

Ao tentar estabelecer as relações de parentesco das espécies os biólogos constroem árvores filogenéticas comparáveis às árvores genealógicas que mostram o parentesco dos nossos familiares. Numa árvore ou arbusto, as folhas encontram-se em galhos, raminhos, ramos, pernadas, troncos secundários e troncos principais, mas se tentarmos agrupar cada folha de um arbusto num ‘ranking’ Lineano, veremos que estamos perante uma tarefa hercúlea, difícil de alcançar.

Vejamos num exemplo concreto: os vertebrados. A classificação clássica (não evolutiva) agrupa-os em cinco classes: os peixes, anfíbios, répteis, aves e mamíferos. Contudo sabemos agora que as aves são descendentes dos dinossauros, que por sua vez são répteis (ou seja, pertencem ao grupo Reptilia), logo, as aves são répteis. Algo que faz sentido se agruparmos os animais numa árvore, na qual o "ramo" das aves é agrupado no "tronco" dos répteis, e esquecemos as categorias filo, classe, ordem, etc. De outra forma, temos uma 'classe' (Aves) dentro de outra 'classe' (Reptilia), que usando a analogia atrás, seria arrumar uma gaveta dentro de outra gaveta. É algo que não existe.

The circulatory system in a phylogenetic context for non-vertebrate deuterostomes

Tunicates (Urochordata) do not have a closed circulatory system, only craniates have the first epithelial ducts that transport oxygen to the locomotion and digestive system-related muscles. However, a small “heart” spreads via peristaltic movements oxygen dissolved in water that circulates through the body. The case in Cephalochordata is even more bizarre since there is no real organ that spreads oxygen through the body. By the contrary the isosmotic fluids run through the body and will eventually reach each cell. In craniates, both the evolutionary novelty of hemoglobin and the heart significantly increase the efficiency of gaseous transactions in the body, which is linked to the characteristic high mobility and levels of activity in craniates.

The evolution of the nervous system in a phylogenetic context for non-vertebrate deuterostomes

The rudiments of a nervous system with the main functional divisions only came to existence in basal craniates (the most inclusive clade containing Myxiginiformes). A fundamental key unavoidably linked to the evolution of the nervous system is locomotion. An animal moving though the space needs to have a representation of what is surrounding it. In deuterostomes, such is the case in tunicate larvae. Before settling in a fixed spot the tunicate larvae are able to move around the 3-dimensional space with the help of a postanal tail. In order to have a clearer notion to where it is going the larvae have a cluster of photosentive cells in the foremost part of the anterior part of the body, which is then linked to a central command that regulates muscle action, this corresponds to the neural tube and notochord. Incredibly, once the tunicate larva settles it eats its own “brain” as energy supply since a “visual” representation of the surrounding environment is not necessary anymore to perform the basic tasks for survival; tunicates are filter-feeders. Nevertheless a ganglion and a subneural gland are maintained in some species and their function is poorly understood.
Amphioxus, and other cephalochordates, is more mobile (i.e. higher levels of activity) and expectadly retain their nervous system through all stages of ontogeny. Cephalochordates are essentially flat swimmers that bear lateral muscles that are controlled by a notochord and neural tube. By sending signals to the lateral mucles the amphioxus can control its turgidity while in locomotion. Again, a pigment spot in the foremost part of the body allows these creatures to acquire electromagnetic information about the surrounding world. Nevertheless, for the most part cephalochordates are passive filter feeders that live penetrated in the sand with the anterior portion of the body protruding to acquire small food items.
Craniates, again, associated to higher levels of activity, further expand their perception of the environment in a number of ways. Hagfish for example have an accurate sense of smell that enables them to search for carcasses to feed and tactile protuberant organ at the tip of the body. These animals are entirely mobile, and therefore, linked to the sensory organs they have a tripartite brain. Other evolutionary novelties were acquired, namely the neurogenic placodes and cranial nerves possibly increasing the efficiency of the nervous system. Importantly, neurogenic placodes are pockets of neurons that are linked to the ampullary organs and to the lateral line that is electrically sensible. In basal craniates gustatory, tactile, olfactory sense systems were already present. Also neural crest cells have a role on 1) the formation of the gill arch skeleton, 2) cranial motor neurons, 3) sensory neurons and 4) dentine and enamel formation.
Echinodermata developed a radial “nervous” system unparalleled in other deuterostomes, several “nerves” radiate from the mouth to the tip of the arms and are composed of interconnected neurons.
Enteropnests (Hemichordata) are essentially tactile animals and they have developed a subepidermal layer of neurons which are more densely concentrated either in the dorsal and ventral part of the body. These layers in conjunction with the stomochord served the base to postulate the origin of the neurogenic placodes and neural crests in craniates.

Entrevista a Phil Mannion, PhD Student

RA: How can we assess diversity from 65M.y old creatures?

PM: We can do simple things like counting the number of genera or species through time. This gives us a rough idea of fluctuations in diversity. However, this can be affected by various processes in the geological record, so, we need to consider where the amount of terrestrial rock varies through time, for instance. Maybe if we have an increase of rock exposure and an increase in diversity, so that increase cannot be genuine. So we can plot diversity against rock record and various proxies like that. We can also correct phylogenies. We know phylogenies are hypothesis of relationships, so we can use those lineages against time and we get another view and explore taxic diversity.

RA: OK, but that has an underlying assumption which is valid. How can this affect your work?

PM: Yes, a phylogeny is only a hypothesis and there is space for mistake in there. We hope that most of the space is small, so it won’t make much difference. Perhaps if a group is in a completely wrong place we will get very long ghost-lineages and the reason why we haven’t look at any taxon there is not because there is a ghost-lineage, but that we just got things wrong. However if you do things like phylogenetic diversity estimate and you do it to various proxies, such as the rock record, than hopefully you can compare them all and you start seeing certain points where you get the same results again and again.

RA: What are the next steps on your research?

PM: The real next step is to finish my thesis! [laughs] I should finish it in the next four to five months.

RA: No… but I mean in scientific terms?...

PM: Well, yeah… Carry on the diversity work. Trying to resolve where the taxic diversity is genuine or logically predicted from the fluctuations of the rock record. And that is sort of near an end. But I also want to go on broader macroevolutionary questions, look at what happened at the K-T boundary. And also use the methodologies I have used for my PhD to other groups like lissamphibians and sharks.

RA: This is a broad question that I have also made to Paul. What is lacking in the Vertebrate Paleontology community?

PM: mmmhh.. We need sauropods to be feathered! [laughs] I think it is getting better, people are applying better methodologies and using things like statistics… more and more people are getting more rigorous with their analysis. Nevertheless, I think people shoud be more rigorous in terms of ages of formations, there are lots of problems in places in China for example. But I think there is still a lot of scope for many avenues in paleontology…

RA: What is a typical day for you as a paleontologist?

PM: A typical day will, at the moment, largely involves me processing large amounts of data through my database of sauropod occurrences and testing it from various criteria to do things like environmental associations, and gradually – somewhat groovenly – writing up my thesis. When I am not doing something directly related with my thesis I am writing descriptive papers, or sometimes coming to Museums like Lourinhã to study specimens.

Entrevistas aos bochechos: 10ª pergunta ao Paul Upchurch

RA: A random question now, but I think it is interesting to think about this sort of things, can vertebrate paleontology be a profitable science?

PU: I think you can argue it already is in some ways. It is quite clear that the general public are interested in dinosaurs in particular, but paleontology in general. So I think there are a number of roots through which paleontology can be economically viable. There is obviously museum work, educational work, work with the media, or, manufacturing casts for museums. In the States, for example, people actually pay in order to dig dinosaurs. There are a number of ways in which the subject canearn money… and I’ve just mentioned a few of them, there are things like writing books and so on. But I think it is absolutely crucial that governments continue to fund paleontology because it is a fragile science. It is one that we do out of interest, rather than something that is going to cure cancer. It has two important contributions that mean the government should want to fund it: the first one is educational, particularly if we can attract children to science… they don’t have to become paleontologist, they can become doctors or engineers. But, if we can inspire them to be interested in science in first place, I think that paleontology and particularly dinosaurs are good ambassadors.

Entrevistas aos bochechos: 8ª pergunta ao Paul Upchurch

RA: Now, just a general broad question: what would you change in the Vertebrate Paleontology community? What do we need? What is still lacking in our community?

PU: Across the community as a whole we’re pursuing very interesting lines of research, but my personal view is that there are two or three things that we could change a little bit. One is there is still a tendency to think that the final goal of a publication is to produce a cladogram, and I think that is a good starting point… but you have to use it to investigate macroevolutionary issues. The second thing is that we need to become more quantitative in our approaches, we still tend to be viewed by non-paleontologists – perhaps quite unfairly – as a hand-waiving area…one that has a lot of speculation and not does not rely very much on facts or analysis. We actually have the ability to analyze data in a quantitive/statistical fashion, we need more of that… and some of our invertebrate paleontology colleagues are leading the way. The final thing that I think we need to change, which is much closer to my particular interests, is that nearly all the papers that discuss biogeography are essentially speculative. They look at the fossil record, they see the various organisms at various places and various points in time, and they build a story around them. This is not adequate testing of the hypothesis. My view is that we need move from, what is called in philosophical terms, the narrative/story-telling phase. What we need to move into is a more analytical phase, where we actually reject hypothesis or verify them by getting large amounts of data and analyze it quantitatively. The same reasoning holds true for all aspects of paleobiology: we need to become more quantitative in diversity, evolution and things like that.

Entrevistas aos bochechos: 7ª pergunta ao Paul Upchurch

RA: Going back a little bit on the sequence of questions, I think that your work on area cladograms and biogeography gives very interesting support where to look for dinosaurs and pursue new taxa. First of all, do you agree with this? And second, if you would have to use this data, where would you work for new taxa?

PU: The biogeographic approach I use, they provide some explanation why some types of dinosaur appear or do not appear in certain places and certain points in time. But of course, that can always be falsified by new discoveries. What I think that is more relevant to directly finding or targeting new localities is the work that my student and in conjunction with me is doing, we’ve built an almost comprehensive database of sauropod occurrences. So what that allows is an analysis like: do sauropod appears in certain types of sediments more often than others; are there areas of the earth that have produced poor quality sauropod material or good quality sauropod material? So I think large scale database are probably the future to a scientific approach to know where to go to collect new material.

Entrevistas aos bochechos: 6ª pergunta ao Paul Upchurch

RA: So, the other area of your research is to look specifically at the evolution of sauropods. Could you outline in broad terms the evolution of the group?

PU: Essentially, they appeared in the Late Triassic; at that stage we call them sauropodomorphs. They are generally small animals, 1-2meters long, they are bipedal… but they still show one or two key features of the sauropodomorphs: relatively long neck, a small head on that neck and some changes to the jaws and teeth, which is suggesting that they are changing from carnivores to omnivores or omnivores to herbivores. Then in the Jurassic, those small forms disappear and we see a trend towards a larger and larger body size, quadrupedality, elongation of the neck and further modifications of the skull. So we get a radiation of the true sauropods, which by the Jurassic have achieved gigantic body size (20-25m). We also see a radiation of many types of sauropods: diplodocoids, early titanosaurs, brachiosaurs, and so on… Then, at the Jurassic/Cretaceous boundary there seems to be a crisis, about 80% of the sauropods go extinct, mainly the ones with the very large spoon-shape teeth. In the Late Cretaceous, sauropod faunas are dominated by the titanosaurs. There are other types like the rebbachisaurs – that were unusual types of diplodocoids – but they radiate again, the also become very diverse. By the end of the Cretaceous there were about 50 or 60 titanosaur genera, which is about one third of sauropod diversity. At the K-T boundary all of those disappear.

Entrevistas aos bochechos: 5ª pergunta ao Paul Upchurch

RA: In which sense are dinosaurs the best clade to test this sort of tools?

PU: I don’t think they are the best clade, but they are one of the best clades. They are a good place to start because they have a relatively rich fossil record, they have a long fossil record – that spans several geographical events –, they have a virtually global distribution; so they can pick up episodes like the break-up of the continents, changes in sea level. And, of course, relative to other groups they are intensively studied; there are far more people working with dinosaurs in the Mesozoic than there are, say, on crocodiles or lizards. But, I think, the best way to analyze biogeographic history is to take multiple groups, ideally groups that have different groups that have different body sizes and different physiologies. If we show that flowering plants, insects, small mammals and dinosaurs are all showing the same patterns, that reinforces the evidence that, despite differences, in the way they live these groups are all affected to the same geographic events. So, I started with dinosaurs because that is my strength, that is my area of interest… but I am interested expanding the work to other groups as well, or, encourage my colleagues to apply the same methods.

Entrevistas aos bochechos: 4ª pergunta ao Paul Upchurch

RA: Yeah, one of the methodological tools that came out from this sort of ideas were area cladograms, wasn’t it?

PU: Area cladograms are an older idea, they go back to the original work done in the 1970’s. But, there is a fundamental problem with an area cladogram which is that by definition a cladogram shows branching structure. And that is fine when you are dealing with organisms that have a nice branching structure phylogeny. The problem is that an area cladogram isn’t describing the evolution of organisms, it is describing the relationships between geographic areas. And geographic areas do not have to obey a branching pattern. They can break up from each other, but they can also collide…they can reconnect. That means that the history of geographic areas is a complext network and not a simple branching pattern. So, the area cladogram by itself is a good idea, but not sufficient to describe biogeographic history. Where the time slicing idea comes in is that you continue to produce area cladograms, but each area cladogram is different for each point in time. By looking how each area cladograms change from each point in time, to the next, to the next, to the next…those changes tell you about the network-like history
Between the areas. So, to give you an example, in the Early Cretaceous we find that South America and Africa cluster together in the area cladogram, we’d say Australia would be more distant – as it was – and then in the Late Cretaceous we find actually that South America and Australia are clustering together with Africa being further away. What we see is a change in the area cladogram structure and, what that means is that between the Early Creataceous and Late Cretaceous that has been some change in biogeography, that cannot be expressed by one area cladogram but by two in sequence. And so, what we are really doing is trying to express this really complex network of area relationships as a series of area cladograms, rather than one area cladogram

Entrevistas aos bochechos: 3ª pergunta ao Paul Upchurch

RA: But isn’t it somehow stratocladistics… isn’t it the same?

PU: No, because in stratocladistics what you do is, when you are building your evolutionary tree you add information on the stratigraphic positions of the organisms and that has an influence on the tree. What I propose is that you keep building evolutionary trees in a conventional manner – using morphological characters or molecular characters if you are working with living organisms. Now, once you have that evolutionary tree you should is analyze biogeography within a certain defined time window. So if I’ve built an evolutionary tree of all dinosaurs in the Early Cretaceous, what I should do is then remove any dinosaurs that are not from the Early Cretaceous. And although that sounds like a bad idea – it sounds like you are throwing away data – the good thing about it is that it helps us focusing on the patterns that happen in the Early Cretaceous. If I can give you an analogy: if I listen to a music and ask you to describe that piece of music in mathematical terms; for one piece of music that might be relatively easy… if I play two pieces of music at the same time it starts to get a little bit confusing, if I play a thousand pieces of music it is almost impossible to understand anything… the problem is if you take a very large dataset. Let’s say all vertebrates from the Triassic up to the present, there are so many different patterns that are so different from each other, they conflict. The idea is to slice in narrow chunks of time, and analyze each of those for biogeographic patterns.